diff --git a/.gitignore b/.gitignore
index f4b95e2..7eeb1d2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,4 +34,4 @@ config.yaml
 past/
 
 # Private interview template content
-frontend/src/util/templateContent.ts
\ No newline at end of file
+frontend/src/util/reactTemplateContent.ts
\ No newline at end of file
diff --git a/Dockerfile.runner b/Dockerfile.runner
new file mode 100644
index 0000000..6437d46
--- /dev/null
+++ b/Dockerfile.runner
@@ -0,0 +1,26 @@
+# Build stage
+FROM golang:1.25-alpine AS build
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o runner ./cmd/runner
+
+# Production stage
+FROM alpine:latest
+
+RUN apk --no-cache add ca-certificates docker-cli && \
+    ln -s /usr/bin/docker /usr/local/bin/docker
+
+WORKDIR /app
+
+COPY --from=build /app/runner .
+COPY --from=build /app/config ./config
+COPY --from=build /app/docker ./docker
+
+EXPOSE 0
+
+CMD ["./runner"]
diff --git a/cmd/runner/main.go b/cmd/runner/main.go
new file mode 100644
index 0000000..4cbf5a9
--- /dev/null
+++ b/cmd/runner/main.go
@@ -0,0 +1,145 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+
+	"goderpad/config"
+	"goderpad/execution"
+	"goderpad/models"
+	"goderpad/redisclient"
+	"goderpad/services"
+)
+
+const runnerGroup = "runners"
+
+func runnerConsumerName() string {
+	hostname, _ := os.Hostname()
+	return "runner-" + hostname
+}
+
+func main() {
+	if err := config.Load("config/config.yml"); err != nil {
+		log.Fatalf("failed to load config: %v", err)
+	}
+
+	if err := redisclient.Init(); err != nil {
+		log.Fatalf("failed to connect to redis: %v", err)
+	}
+	defer redisclient.Close()
+
+	// Build sandbox Docker images before accepting jobs
+	if config.GetEnableCodeExecution() {
+		execution.BuildImages()
+	}
+
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	rdb := redisclient.GetClient()
+	consumer := runnerConsumerName()
+
+	// Create consumer group for the jobs stream
+	err := rdb.XGroupCreateMkStream(ctx, services.JobsStream, runnerGroup, "0").Err()
+	if err != nil && err.Error() != "BUSYGROUP Consumer Group name already exists" {
+		log.Printf("warning: could not create jobs consumer group: %v", err)
+	}
+
+	log.Printf("code runner started (consumer=%s), waiting for jobs...", consumer)
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("runner shutting down")
+			return
+		default:
+		}
+
+		streams, err := rdb.XReadGroup(ctx, &redis.XReadGroupArgs{
+			Group:    runnerGroup,
+			Consumer: consumer,
+			Streams:  []string{services.JobsStream, ">"},
+			Count:    1,
+			Block:    5 * time.Second,
+		}).Result()
+
+		if err != nil {
+			if err == redis.Nil || ctx.Err() != nil {
+				continue
+			}
+			log.Printf("error reading jobs stream: %v", err)
+			time.Sleep(1 * time.Second)
+			continue
+		}
+
+		for _, stream := range streams {
+			for _, msg := range stream.Messages {
+				processJob(ctx, rdb, msg)
+			}
+		}
+	}
+}
+
+func processJob(ctx context.Context, rdb *redis.Client, msg redis.XMessage) {
+	data, ok := msg.Values["data"].(string)
+	if !ok {
+		log.Printf("invalid job message: %s", msg.ID)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	var job models.ExecuteJob
+	if err := json.Unmarshal([]byte(data), &job); err != nil {
+		log.Printf("failed to unmarshal job: %v", err)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	log.Printf("executing job %s: %s for room %s", job.JobID, job.Language, job.RoomID)
+
+	result := models.ExecuteResult{
+		JobID:  job.JobID,
+		RoomID: job.RoomID,
+		UserID: job.UserID,
+	}
+
+	execResult, err := execution.RunCode(job.Language, job.Code)
+	if err != nil {
+		result.Stdout = ""
+		result.Stderr = err.Error()
+		result.Code = -1
+	} else {
+		result.Stdout = execResult.Stdout
+		result.Stderr = execResult.Stderr
+		result.Code = execResult.Code
+	}
+
+	// Publish result back to Redis
+	resultData, err := json.Marshal(result)
+	if err != nil {
+		log.Printf("failed to marshal result for job %s: %v", job.JobID, err)
+		rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+		return
+	}
+
+	if err := rdb.XAdd(ctx, &redis.XAddArgs{
+		Stream: services.ResultsStream,
+		MaxLen: 1000,
+		Approx: true,
+		Values: map[string]interface{}{
+			"data": string(resultData),
+		},
+	}).Err(); err != nil {
+		log.Printf("failed to publish result for job %s: %v", job.JobID, err)
+	}
+
+	rdb.XAck(ctx, services.JobsStream, runnerGroup, msg.ID)
+	log.Printf("completed job %s (exit code: %d)", job.JobID, result.Code)
+}
diff --git a/cmd/server/main.go b/cmd/server/main.go
index b89cef6..21b3aeb 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -1,16 +1,21 @@
 package main
 
 import (
+	"context"
 	"log"
+	"os/signal"
 	"strconv"
+	"syscall"
 
 	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
 	"goderpad/config"
+	"goderpad/execution"
 	"goderpad/handlers"
 	"goderpad/metrics"
+	"goderpad/redisclient"
 	"goderpad/services"
 )
 
@@ -36,8 +41,10 @@ func main() {
 		})
 	})
 
+	r.POST("/execute", handlers.ExecuteHandler)
 	r.POST("/createRoom", handlers.CreateRoomHandler)
 	r.POST("/joinRoom", handlers.JoinRoomHandler)
+	r.POST("/switchLanguage", handlers.SwitchLanguageHandler)
 	r.GET("/getRoomName/:roomID", handlers.GetRoomNameHandler)
 	r.GET("/past/:roomID", handlers.GetDocumentSaveHandler)
 	r.GET("/validateKey", handlers.ValidateKeyHandler)
@@ -48,6 +55,19 @@ func main() {
 
 	go services.DeleteRoomSaves()
 
+	if config.GetEnableCodeExecution() {
+		go execution.BuildImages()
+
+		if err := redisclient.Init(); err != nil {
+			log.Fatalf("Failed to connect to Redis: %v", err)
+		}
+		defer redisclient.Close()
+
+		ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+		defer stop()
+		go services.StartResultListener(ctx)
+	}
+
 	r.Run(":" + config.GetPort())
 }
 
diff --git a/config/config.example.yml b/config/config.example.yml
index 5b98312..9df7319 100644
--- a/config/config.example.yml
+++ b/config/config.example.yml
@@ -1,6 +1,13 @@
 server:
   port: YOUR_PORT_HERE
   api_key: YOUR_API_KEY_HERE
+  enable_code_execution: false
+  docker_binary_path: ""  # leave empty to use "docker" from $PATH, or set full path e.g. /usr/local/bin/docker
   allowed_origins:
     - "http://localhost:7777"
-    - "http://localhost:5173"
\ No newline at end of file
+    - "http://localhost:5173"
+
+redis:
+  addr: "localhost:6379"
+  password: ""
+  db: 0
\ No newline at end of file
diff --git a/config/config.go b/config/config.go
index 5bff060..668634c 100644
--- a/config/config.go
+++ b/config/config.go
@@ -9,12 +9,21 @@ import (
 
 type Config struct {
 	Server ServerConfig `yaml:"server"`
+	Redis  RedisConfig  `yaml:"redis"`
+}
+
+type RedisConfig struct {
+	Addr     string `yaml:"addr"`
+	Password string `yaml:"password"`
+	DB       int    `yaml:"db"`
 }
 
 type ServerConfig struct {
-	Port           string   `yaml:"port"`
-	APIKey         string   `yaml:"api_key"`
-	AllowedOrigins []string `yaml:"allowed_origins"`
+	Port                  string   `yaml:"port"`
+	APIKey                string   `yaml:"api_key"`
+	AllowedOrigins        []string `yaml:"allowed_origins"`
+	EnableCodeExecution bool `yaml:"enable_code_execution"`
+	DockerBinaryPath      string   `yaml:"docker_binary_path"`
 }
 
 var AppConfig Config
@@ -45,3 +54,32 @@ func GetAPIKey() string {
 func GetAllowedOrigins() []string {
 	return AppConfig.Server.AllowedOrigins
 }
+
+func GetEnableCodeExecution() bool {
+	return AppConfig.Server.EnableCodeExecution
+}
+
+func GetRedisAddr() string {
+	if env := os.Getenv("REDIS_ADDR"); env != "" {
+		return env
+	}
+	if AppConfig.Redis.Addr != "" {
+		return AppConfig.Redis.Addr
+	}
+	return "localhost:6379"
+}
+
+func GetRedisPassword() string {
+	return AppConfig.Redis.Password
+}
+
+func GetRedisDB() int {
+	return AppConfig.Redis.DB
+}
+
+func GetDockerBinaryPath() string {
+	if AppConfig.Server.DockerBinaryPath != "" {
+		return AppConfig.Server.DockerBinaryPath
+	}
+	return "docker"
+}
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
index 36b42b4..9d328ce 100644
--- a/docker-compose.dev.yml
+++ b/docker-compose.dev.yml
@@ -1,4 +1,12 @@
 services:
+  goderpad-redis:
+    image: redis:7-alpine
+    container_name: goderpad-redis
+    ports:
+      - "6379:6379"
+    profiles:
+      - code-execution
+
   goderpad-backend:
     build:
       context: .
@@ -6,9 +14,25 @@ services:
     container_name: goderpad-backend
     ports:
       - "7778:7778"
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
     volumes:
       - ./past:/app/past
 
+  goderpad-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.runner
+    container_name: goderpad-runner
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    depends_on:
+      - goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-frontend:
     build:
       context: ./frontend
@@ -24,7 +48,7 @@ services:
     environment:
       - VITE_API_URL=http://localhost:7778
       - VITE_WS_URL=ws://localhost:7778
-    
+
   goderpad-nginx:
     image: nginx:alpine
     volumes:
diff --git a/docker-compose.yml b/docker-compose.yml
index 74c4588..e70d344 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,12 +1,34 @@
 services:
+  goderpad-redis:
+    image: redis:7-alpine
+    container_name: goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-backend:
     build:
       context: .
       dockerfile: Dockerfile.backend
     container_name: goderpad-backend
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
     volumes:
       - ./past:/app/past
 
+  goderpad-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.runner
+    container_name: goderpad-runner
+    environment:
+      - REDIS_ADDR=goderpad-redis:6379
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    depends_on:
+      - goderpad-redis
+    profiles:
+      - code-execution
+
   goderpad-nginx:
     build:
       context: .
diff --git a/docker/cpp.Dockerfile b/docker/cpp.Dockerfile
new file mode 100644
index 0000000..be5fe9b
--- /dev/null
+++ b/docker/cpp.Dockerfile
@@ -0,0 +1,2 @@
+FROM alpine:3.20
+RUN apk add --no-cache g++
diff --git a/docker/java.Dockerfile b/docker/java.Dockerfile
new file mode 100644
index 0000000..48418f0
--- /dev/null
+++ b/docker/java.Dockerfile
@@ -0,0 +1 @@
+FROM eclipse-temurin:21-jdk-alpine
diff --git a/docker/javascript.Dockerfile b/docker/javascript.Dockerfile
new file mode 100644
index 0000000..f0e004a
--- /dev/null
+++ b/docker/javascript.Dockerfile
@@ -0,0 +1 @@
+FROM node:20-alpine
diff --git a/docker/python.Dockerfile b/docker/python.Dockerfile
new file mode 100644
index 0000000..21047e8
--- /dev/null
+++ b/docker/python.Dockerfile
@@ -0,0 +1 @@
+FROM python:3.12-alpine
diff --git a/execution/execution.go b/execution/execution.go
new file mode 100644
index 0000000..869ad19
--- /dev/null
+++ b/execution/execution.go
@@ -0,0 +1,126 @@
+package execution
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"log"
+	"os/exec"
+	"strings"
+	"time"
+
+	"goderpad/config"
+)
+
+const ExecutionTimeout = 20 * time.Second
+
+type LangConfig struct {
+	Image      string
+	Dockerfile string
+	Filename   string
+	Command    string
+}
+
+var LanguageConfigs = map[string]LangConfig{
+	"python": {
+		Image:      "goderpad-python",
+		Dockerfile: "docker/python.Dockerfile",
+		Filename:   "main.py",
+		Command:    "cat > /tmp/main.py && python3 /tmp/main.py",
+	},
+	"javascript": {
+		Image:      "goderpad-javascript",
+		Dockerfile: "docker/javascript.Dockerfile",
+		Filename:   "main.js",
+		Command:    "cat > /tmp/main.js && node /tmp/main.js",
+	},
+	"c++": {
+		Image:      "goderpad-cpp",
+		Dockerfile: "docker/cpp.Dockerfile",
+		Filename:   "main.cpp",
+		Command:    "cat > /tmp/main.cpp && g++ -o /tmp/main /tmp/main.cpp && /tmp/main",
+	},
+	"java": {
+		Image:      "goderpad-java",
+		Dockerfile: "docker/java.Dockerfile",
+		Filename:   "Main.java",
+		Command:    "cat > /tmp/Main.java && javac -d /tmp /tmp/Main.java && java -cp /tmp Main",
+	},
+}
+
+type Result struct {
+	Stdout string `json:"stdout"`
+	Stderr string `json:"stderr"`
+	Code   int    `json:"code"`
+}
+
+// BuildImages builds each language sandbox image from its Dockerfile.
+func BuildImages() {
+	for lang, cfg := range LanguageConfigs {
+		log.Printf("building execution image for %s...", lang)
+		cmd := exec.Command(config.GetDockerBinaryPath(), "build", "-t", cfg.Image, "-f", cfg.Dockerfile, ".")
+		if out, err := cmd.CombinedOutput(); err != nil {
+			log.Printf("error building %s image: %v\n%s", lang, err, out)
+		} else {
+			log.Printf("built execution image for %s", lang)
+		}
+	}
+}
+
+// RunCode executes user code in a sandboxed Docker container.
+// Code is piped via stdin to avoid volume mounts, which don't work
+// when the runner itself is inside a container (Docker-in-Docker).
+func RunCode(language, code string) (*Result, error) {
+	cfg, ok := LanguageConfigs[language]
+	if !ok {
+		return nil, fmt.Errorf("unsupported language: %s", language)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), ExecutionTimeout)
+	defer cancel()
+
+	args := []string{
+		"run", "--rm", "-i",
+		"--network=none",
+		"--memory=256m",
+		"--memory-swap=256m",
+		"--cpus=0.25",
+		"--pids-limit=64",
+		"--read-only",
+		"--tmpfs=/tmp:exec,size=32m",
+		cfg.Image,
+		"sh", "-c", cfg.Command,
+	}
+
+	cmd := exec.CommandContext(ctx, config.GetDockerBinaryPath(), args...)
+	cmd.Stdin = strings.NewReader(code)
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+
+	if ctx.Err() == context.DeadlineExceeded {
+		return &Result{
+			Stdout: stdout.String(),
+			Stderr: "execution timed out (20s limit)",
+			Code:   -1,
+		}, nil
+	}
+
+	exitCode := 0
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok {
+			exitCode = exitErr.ExitCode()
+		} else {
+			return nil, fmt.Errorf("docker unavailable — is it installed and running? (%v)", err)
+		}
+	}
+
+	return &Result{
+		Stdout: stdout.String(),
+		Stderr: stderr.String(),
+		Code:   exitCode,
+	}, nil
+}
diff --git a/frontend/src/api/api.ts b/frontend/src/api/api.ts
index aa5e896..8c9d2ac 100644
--- a/frontend/src/api/api.ts
+++ b/frontend/src/api/api.ts
@@ -1,6 +1,19 @@
 const API_URL = import.meta.env.VITE_API_URL || 'http://localhost:7778';
 
-export async function createRoom(userId: string, name: string, roomName: string, initialCode?: string) {
+export async function executeCode(language: string, code: string) {
+  try {
+    const response = await fetch(`${API_URL}/execute`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ language, code }),
+    });
+    return await response.json();
+  } catch (err) {
+    return { ok: false, error: err instanceof Error ? err.message : 'failed to reach execution service' };
+  }
+}
+
+export async function createRoom(userId: string, name: string, roomName: string, language: string, initialCode?: string) {
   try {
     const response = await fetch(`${API_URL}/createRoom`, {
       method: 'POST',
@@ -11,6 +24,7 @@ export async function createRoom(userId: string, name: string, roomName: string,
         userId,
         name,
         roomName,
+        language,
         ...(initialCode !== undefined && { initialCode }),
       }),
     });
@@ -45,6 +59,24 @@ export async function joinRoom(userId: string, name: string, roomId: string) {
   }
 }
 
+export async function switchLanguage(roomId: string, language: string) {
+  try {
+    const response = await fetch(`${API_URL}/switchLanguage`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify({ roomId, language }),
+    });
+    return await response.json();
+  } catch (err) {
+    return {
+      ok: false,
+      error: err instanceof Error ? err.message : 'Error switching language'
+    };
+  }
+}
+
 export async function getRoomName(roomId: string) {
   try {
     const response = await fetch(`${API_URL}/getRoomName/${roomId}`);
diff --git a/frontend/src/components/home/HomePage.tsx b/frontend/src/components/home/HomePage.tsx
index b5d2c12..f3734f1 100644
--- a/frontend/src/components/home/HomePage.tsx
+++ b/frontend/src/components/home/HomePage.tsx
@@ -1,53 +1,75 @@
 import React, { useState, useContext, useEffect } from 'react';
 import { createRoom, validateApiKey } from '../../api/api';
 import { useNavigate } from 'react-router-dom';
-import { DarkModeContext } from '../../App';
-import { UserContext } from '../../App';
+import { DarkModeContext, UserContext } from '../../App';
 import Popup from '../popup/Popup';
+import { TEMPLATES, DEFAULT_CODE as DEFAULT_REACT_CODE } from '../../util/reactTemplateContent';
+import { type InterviewType } from '../room/CodeEditor';
+
+interface TemplateCard {
+  name: string;
+  description: string;
+  code: string;
+  interviewType: InterviewType;
+}
+
+const REACT_CARD: TemplateCard = {
+  name: 'react interview',
+  description: 'build and run a react component in real time',
+  code: DEFAULT_REACT_CODE,
+  interviewType: 'react',
+};
+
+const LEETCODE_CARD: TemplateCard = {
+  name: 'leetcode interview',
+  description: 'write code in python, c++, java, or javascript',
+  code: `def main():\n    print("Hello, World!")\n\nmain()`,
+  interviewType: 'leetcode',
+};
+
+// Non-standard templates require an API key — exclude 'standard' since REACT_CARD already covers it
+const EXTRA_TEMPLATES: TemplateCard[] = TEMPLATES
+  .filter(t => t.name !== 'standard')
+  .map(t => ({ ...t, interviewType: 'react' as InterviewType }));
 
 function HomePage() {
   const { isDark } = useContext(DarkModeContext);
   const [userName, setUserName] = useState('');
   const [roomName, setRoomName] = useState('');
   const [showPopup, setShowPopup] = useState(false);
+  const [showTemplateModal, setShowTemplateModal] = useState(false);
   const [showApiKeyModal, setShowApiKeyModal] = useState(false);
   const [apiKeyInput, setApiKeyInput] = useState('');
   const [apiKeyError, setApiKeyError] = useState('');
   const [isValidating, setIsValidating] = useState(false);
+  const [isAuthenticated, setIsAuthenticated] = useState(false);
   const navigate = useNavigate();
   const { userId } = useContext(UserContext);
 
-  const handleCreateRoom = async () => {
-    let response;
-    if (roomName === '') {
-      response = await createRoom(userId, userName, `${userName}'s sce interview`);
-    } else {
-      response = await createRoom(userId, userName, roomName);
-    }
-    if (response.ok) {
-      const roomId = response.data.roomId;
-      const expiry = new Date().getTime() + (24 * 60 * 60 * 1000); // 24 hours
-      const data = JSON.stringify({ userName, expiry });
-      localStorage.setItem(`goderpad-cookie-${roomId}`, data);
-      navigate(`/${roomId}`);
-    } else {
-      setShowPopup(true);
-    }
-  };
-
   useEffect(() => {
-    if (!showApiKeyModal) return;
     const handleKeyDown = (e: KeyboardEvent) => {
-      if (e.key === 'Escape') setShowApiKeyModal(false);
+      if (e.key === 'Escape') {
+        if (showApiKeyModal) setShowApiKeyModal(false);
+        else if (showTemplateModal) setShowTemplateModal(false);
+      }
     };
     window.addEventListener('keydown', handleKeyDown);
     return () => window.removeEventListener('keydown', handleKeyDown);
-  }, [showApiKeyModal]);
+  }, [showApiKeyModal, showTemplateModal]);
 
-  const handleTemplateButtonClick = () => {
-    setApiKeyInput('');
-    setApiKeyError('');
-    setShowApiKeyModal(true);
+  const handleSelectTemplate = async (template: TemplateCard) => {
+    const finalRoomName = roomName || template.name;
+    const language = template.interviewType === 'leetcode' ? 'python' : 'react';
+    const response = await createRoom(userId, userName, finalRoomName, language, template.code);
+    if (response.ok) {
+      const roomId = response.data.roomId;
+      const expiry = new Date().getTime() + (24 * 60 * 60 * 1000);
+      localStorage.setItem(`goderpad-cookie-${roomId}`, JSON.stringify({ userName, expiry }));
+      navigate(`/${roomId}`, { state: { interviewType: template.interviewType } });
+    } else {
+      setShowTemplateModal(false);
+      setShowPopup(true);
+    }
   };
 
   const handleApiKeySubmit = async (e: React.FormEvent) => {
@@ -62,19 +84,25 @@ function HomePage() {
       return;
     }
     sessionStorage.setItem('api_key', apiKeyInput);
-    navigate('/templates', { state: { userName, roomName, userId } });
+    setIsAuthenticated(true);
+    setShowApiKeyModal(false);
   };
 
+  const templates: TemplateCard[] = [
+    REACT_CARD,
+    LEETCODE_CARD,
+    ...(isAuthenticated ? EXTRA_TEMPLATES : []),
+  ];
+
   return (<>
     <Popup
       message="sorry, an error occurred trying to create the room."
       buttonText="ok"
       isOpen={showPopup}
-      onClickButton={() => {
-        setShowPopup(false);
-      }}
+      onClickButton={() => setShowPopup(false)}
     />
-<div className={`min-h-screen ${isDark ? 'bg-slate-900 text-white' : 'bg-gray-100 text-gray-900'}`}>
+
+    <div className={`min-h-screen ${isDark ? 'bg-slate-900 text-white' : 'bg-gray-100 text-gray-900'}`}>
       <h1 className='text-4xl font-bold text-center pt-20'>welcome to goderpad</h1>
       <h3 className='text-xl text-center pt-4'>sce's interview platform</h3>
       <div className='flex flex-row gap-30 justify-center mt-20'>
@@ -88,16 +116,12 @@ function HomePage() {
               type='text'
               value={userName}
               onChange={(e) => setUserName(e.target.value)}
-              onKeyDown={(e) => {
-                if (e.key === 'Enter' && userName.trim()) {
-                  handleCreateRoom();
-                }
-              }}
+              onKeyDown={(e) => { if (e.key === 'Enter' && userName.trim()) setShowTemplateModal(true); }}
               placeholder='enter your name'
               className={`px-5 py-4 text-lg rounded-lg focus:outline-none focus:border-blue-500 ${isDark
-                  ? 'bg-slate-800 border border-slate-700 text-white'
-                  : 'bg-white border border-gray-300 text-gray-900'
-                }`}
+                ? 'bg-slate-800 border border-slate-700 text-white'
+                : 'bg-white border border-gray-300 text-gray-900'
+              }`}
             />
           </div>
 
@@ -110,64 +134,120 @@ function HomePage() {
               type='text'
               value={roomName}
               onChange={(e) => setRoomName(e.target.value)}
-              onKeyDown={(e) => {
-                if (e.key === 'Enter' && userName.trim()) {
-                  handleCreateRoom();
-                }
-              }}
+              onKeyDown={(e) => { if (e.key === 'Enter' && userName.trim()) setShowTemplateModal(true); }}
               placeholder='name your room'
               className={`px-5 py-4 text-lg rounded-lg focus:outline-none focus:border-blue-500 ${isDark
-                  ? 'bg-slate-800 border border-slate-700 text-white'
-                  : 'bg-white border border-gray-300 text-gray-900'
-                }`}
+                ? 'bg-slate-800 border border-slate-700 text-white'
+                : 'bg-white border border-gray-300 text-gray-900'
+              }`}
             />
           </div>
 
           <button
-            onClick={handleCreateRoom}
+            onClick={() => setShowTemplateModal(true)}
             className='mt-4 px-6 py-4 text-lg bg-green-600 text-white rounded-lg hover:bg-green-700 cursor-pointer transition-colors disabled:opacity-50'
             disabled={!userName.trim()}
           >
             create room
           </button>
-
-          <button
-            onClick={handleTemplateButtonClick}
-            className={`text-base cursor-pointer transition-colors underline disabled:opacity-50 disabled:cursor-not-allowed ${isDark ? 'text-white hover:text-gray-300' : 'text-gray-900 hover:text-gray-700'}`}
-            disabled={!userName.trim() || !roomName.trim()}
-          >
-            or choose a template
-          </button>
         </div>
       </div>
     </div>
 
+    {/* Template selection modal */}
+    {showTemplateModal && (
+      <div
+        className='fixed inset-0 z-40 flex items-center justify-center backdrop-blur-sm'
+        onClick={() => setShowTemplateModal(false)}
+      >
+        <div
+          onClick={(e) => e.stopPropagation()}
+          className={`relative rounded-2xl shadow-2xl p-8 w-full max-w-3xl mx-4 max-h-[85vh] overflow-y-auto ${isDark ? 'bg-slate-800' : 'bg-white'}`}
+        >
+          <div className='flex items-center justify-between mb-6'>
+            <h2 className={`text-2xl font-bold ${isDark ? 'text-white' : 'text-gray-900'}`}>choose a template</h2>
+            <button
+              onClick={() => setShowTemplateModal(false)}
+              className={`p-1.5 rounded-lg transition-colors ${isDark ? 'text-gray-400 hover:text-white hover:bg-slate-700' : 'text-gray-500 hover:text-gray-900 hover:bg-gray-100'}`}
+            >
+              <svg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='currentColor' strokeWidth='2' strokeLinecap='round' strokeLinejoin='round'>
+                <line x1='18' y1='6' x2='6' y2='18' /><line x1='6' y1='6' x2='18' y2='18' />
+              </svg>
+            </button>
+          </div>
+
+          <div className={`grid gap-4 ${templates.length > 2 ? 'grid-cols-1 sm:grid-cols-2 lg:grid-cols-3' : 'grid-cols-1 sm:grid-cols-2'}`}>
+            {templates.map((template) => (
+              <button
+                key={template.name}
+                onClick={() => handleSelectTemplate(template)}
+                className={`text-left p-6 rounded-xl border-2 transition-all cursor-pointer hover:scale-[1.02] ${
+                  isDark
+                    ? 'bg-slate-900 border-slate-700 hover:border-green-500'
+                    : 'bg-gray-50 border-gray-200 hover:border-green-500'
+                }`}
+              >
+                <div className='flex items-center gap-2 mb-2'>
+                  <h3 className={`text-base font-semibold ${isDark ? 'text-white' : 'text-gray-900'}`}>{template.name}</h3>
+                  <span className={`text-xs px-2 py-0.5 rounded-full ${
+                    template.interviewType === 'leetcode'
+                      ? isDark ? 'bg-blue-900 text-blue-300' : 'bg-blue-100 text-blue-700'
+                      : isDark ? 'bg-green-900 text-green-300' : 'bg-green-100 text-green-700'
+                  }`}>
+                    {template.interviewType === 'leetcode' ? 'leetcode' : 'react'}
+                  </span>
+                </div>
+                <p className={`text-sm ${isDark ? 'text-gray-400' : 'text-gray-500'}`}>{template.description}</p>
+                <pre className={`mt-3 text-xs rounded-lg p-3 overflow-hidden max-h-20 leading-relaxed ${
+                  isDark ? 'bg-slate-800 text-gray-300' : 'bg-white text-gray-700'
+                }`}>
+                  {template.code.slice(0, 120)}...
+                </pre>
+              </button>
+            ))}
+          </div>
+
+          {!isAuthenticated && (
+            <div className='mt-6 text-center'>
+              <button
+                onClick={() => { setApiKeyInput(''); setApiKeyError(''); setShowApiKeyModal(true); }}
+                className={`text-sm underline transition-colors ${isDark ? 'text-gray-400 hover:text-white' : 'text-gray-500 hover:text-gray-900'}`}
+              >
+                have an api key? unlock more templates
+              </button>
+            </div>
+          )}
+        </div>
+      </div>
+    )}
+
+    {/* API key modal */}
     {showApiKeyModal && (
       <div className='fixed inset-0 z-50 flex items-center justify-center backdrop-blur-sm' onClick={() => setShowApiKeyModal(false)}>
         <form onSubmit={handleApiKeySubmit} onClick={(e) => e.stopPropagation()} className={`rounded-xl shadow-2xl p-8 max-w-sm w-full mx-4 ${isDark ? 'bg-slate-800' : 'bg-white'}`}>
           <h2 className={`text-xl font-bold mb-4 ${isDark ? 'text-white' : 'text-gray-900'}`}>Enter API Key</h2>
           <p className={`text-sm mb-6 ${isDark ? 'text-gray-400' : 'text-gray-600'}`}>An API key is required to access interview templates.</p>
           <input
-            type="password"
+            type='password'
             value={apiKeyInput}
             onChange={(e) => { setApiKeyInput(e.target.value); setApiKeyError(''); }}
-            placeholder="API key"
+            placeholder='API key'
             className={`w-full px-4 py-2 rounded-lg border outline-none mb-2 ${isDark ? 'bg-slate-700 border-slate-600 text-white placeholder-gray-400' : 'bg-gray-50 border-gray-300 text-gray-900'}`}
             autoFocus
           />
-          <p className="text-red-500 text-sm h-5 mb-2">{apiKeyError}</p>
-          <div className="flex gap-3">
+          <p className='text-red-500 text-sm h-5 mb-2'>{apiKeyError}</p>
+          <div className='flex gap-3'>
             <button
-              type="button"
+              type='button'
               onClick={() => setShowApiKeyModal(false)}
               className={`flex-1 px-6 py-2.5 rounded-lg transition-colors font-semibold ${isDark ? 'bg-slate-700 text-white hover:bg-slate-600' : 'bg-gray-100 text-gray-900 hover:bg-gray-200'}`}
             >
               Cancel
             </button>
             <button
-              type="submit"
+              type='submit'
               disabled={!apiKeyInput || isValidating}
-              className="flex-1 px-6 py-2.5 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors font-semibold disabled:opacity-50"
+              className='flex-1 px-6 py-2.5 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors font-semibold disabled:opacity-50'
             >
               {isValidating ? 'Checking...' : 'Continue'}
             </button>
diff --git a/frontend/src/components/room/CodeEditor.tsx b/frontend/src/components/room/CodeEditor.tsx
index 86f3fb7..fd17189 100644
--- a/frontend/src/components/room/CodeEditor.tsx
+++ b/frontend/src/components/room/CodeEditor.tsx
@@ -2,11 +2,33 @@ import Editor from '@monaco-editor/react';
 import { useState, useRef, useContext, useEffect, useCallback } from 'react';
 import { DarkModeContext, UserContext } from '../../App';
 import { SandpackProvider, SandpackPreview } from '@codesandbox/sandpack-react';
+import { switchLanguage } from '../../api/api';
+
+type Language = 'react' | 'javascript' | 'python' | 'cpp' | 'java';
+export type InterviewType = 'react' | 'leetcode';
+
+const LANGUAGE_OPTIONS: { value: Language; label: string; monacoLang: string; sandpackTemplate?: 'react', execLang?: string }[] = [
+  { value: 'react',      label: 'React',      monacoLang: 'javascript', sandpackTemplate: 'react' },
+  { value: 'javascript', label: 'JavaScript', monacoLang: 'javascript' , execLang: 'javascript'},
+  { value: 'python',     label: 'Python',     monacoLang: 'python' , execLang: 'python'},
+  { value: 'cpp',        label: 'C++',        monacoLang: 'cpp' , execLang: 'c++'},
+  { value: 'java',       label: 'Java',       monacoLang: 'java' , execLang: 'java'},
+];
+
+interface RunOutput {
+  stdout: string;
+  stderr: string;
+  code: number | null;
+}
+
+const LEETCODE_LANGUAGES: Language[] = ['python', 'cpp', 'java', 'javascript'];
 
 interface CodeEditorProps {
   code: string;
   setCode: (code: string) => void;
   ws: WebSocket | null;
+  roomId: string;
+  interviewType: InterviewType;
   users: Array<{
     userId: string;
     userName: string;
@@ -23,9 +45,14 @@ interface CodeEditorProps {
   }>;
 }
 
-function CodeEditor({ code, setCode, ws, users }: CodeEditorProps) {
+function CodeEditor({ code, setCode, ws, roomId, interviewType, users }: CodeEditorProps) {
   const { isDark } = useContext(DarkModeContext);
   const { userId } = useContext(UserContext);
+  const [language, setLanguage] = useState<Language>(interviewType === 'leetcode' ? 'python' : 'react');
+  const [langDropdownOpen, setLangDropdownOpen] = useState(false);
+  const [runOutput, setRunOutput] = useState<RunOutput | null>(null);
+  const [isRunning, setIsRunning] = useState(false);
+  const [runError, setRunError] = useState<string | null>(null);
   const editorRef = useRef<any>(null);
   const monacoRef = useRef<any>(null);
   const wsRef = useRef<WebSocket | null>(ws);
@@ -347,13 +374,120 @@ function CodeEditor({ code, setCode, ws, users }: CodeEditorProps) {
     };
   }, [users, userId, visibleLabels]);
 
+  // Listen for execute_result messages on the WebSocket
+  useEffect(() => {
+    if (!ws) return;
+    const handler = (event: MessageEvent) => {
+      const message = JSON.parse(event.data);
+      if (message.type === 'execute_result') {
+        setIsRunning(false);
+        const payload = message.payload;
+        if (payload.stderr && !payload.stdout && payload.code !== 0) {
+          setRunError(payload.stderr);
+        } else {
+          setRunOutput({
+            stdout: payload.stdout,
+            stderr: payload.stderr,
+            code: payload.code,
+          });
+        }
+      }
+    };
+    ws.addEventListener('message', handler);
+    return () => ws.removeEventListener('message', handler);
+  }, [ws]);
+
+  const runCode = () => {
+    if (!selectedLang.execLang) return;
+    if (!ws || ws.readyState !== WebSocket.OPEN) return;
+    setIsRunning(true);
+    setRunOutput(null);
+    setRunError(null);
+    ws.send(JSON.stringify({
+      userId,
+      type: 'execute_request',
+      payload: {
+        language: selectedLang.execLang,
+        code: code,
+      }
+    }));
+  };
+
+  const availableLanguages = interviewType === 'leetcode'
+    ? LEETCODE_LANGUAGES.map(lang => LANGUAGE_OPTIONS.find(l => l.value === lang)!)
+    : LANGUAGE_OPTIONS.filter(l => l.value === 'react');
+  const selectedLang = LANGUAGE_OPTIONS.find(l => l.value === language)!;
+  const showPreview = interviewType === 'react';
+
   return (
-    <div ref={containerRef} className={`flex flex-row ${isDark ? 'bg-slate-900' : 'bg-gray-100'} p-6 pt-20`}>
+    <div ref={containerRef} className={`relative flex flex-row ${isDark ? 'bg-slate-900' : 'bg-gray-100'} p-6 pt-20`}>
+      {/* Language dropdown — only shown for leetcode interviews */}
+      {interviewType === 'leetcode' && <div className='absolute top-6 left-6 z-20'>
+        <div className='relative'>
+          <button
+            onClick={() => setLangDropdownOpen(prev => !prev)}
+            className={`flex items-center gap-2 px-3 py-1.5 rounded-lg text-sm font-medium transition-colors ${
+              isDark
+                ? 'bg-slate-800 text-white hover:bg-slate-700 border border-slate-600'
+                : 'bg-white text-gray-900 hover:bg-gray-200 border border-gray-300'
+            }`}
+          >
+            {selectedLang.label}
+            <svg
+              xmlns='http://www.w3.org/2000/svg'
+              width='14'
+              height='14'
+              viewBox='0 0 24 24'
+              fill='none'
+              stroke='currentColor'
+              strokeWidth='2'
+              strokeLinecap='round'
+              strokeLinejoin='round'
+              className={`transition-transform ${langDropdownOpen ? 'rotate-180' : ''}`}
+            >
+              <polyline points='6 9 12 15 18 9' />
+            </svg>
+          </button>
+          {langDropdownOpen && (
+            <div className={`absolute top-full mt-1 left-0 rounded-lg shadow-lg overflow-hidden border ${
+              isDark ? 'bg-slate-800 border-slate-600' : 'bg-white border-gray-200'
+            }`}>
+              {availableLanguages.map(opt => (
+                <button
+                  key={opt.value}
+                  onClick={async () => {
+                    setLangDropdownOpen(false);
+                    const response = await switchLanguage(roomId, opt.value);
+                    if (response.ok) {
+                      setLanguage(opt.value);
+                      setCode(response.data.document);
+                      if (wsRef.current && wsRef.current.readyState === WebSocket.OPEN) {
+                        wsRef.current.send(JSON.stringify({
+                          userId,
+                          type: 'code_update',
+                          payload: { code: response.data.document }
+                        }));
+                      }
+                    }
+                  }}
+                  className={`w-full text-left px-4 py-2 text-sm transition-colors ${
+                    opt.value === language
+                      ? isDark ? 'bg-slate-700 text-white' : 'bg-gray-100 text-gray-900'
+                      : isDark ? 'text-white hover:bg-slate-700' : 'text-gray-900 hover:bg-gray-100'
+                  }`}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          )}
+        </div>
+      </div>}
       {isDragging && <div className='fixed inset-0 z-50 cursor-col-resize' />}
       <div style={{ width: `${leftPercent}%` }} className={`border-2 ${isDark ? 'border-white' : 'border-gray-900'} rounded-lg overflow-hidden`}>
         <Editor
           height='85vh'
-          defaultLanguage={'javascript'}
+          language={selectedLang.monacoLang}
           value={code}
           theme={isDark ? 'slate-dark' : 'vs'}
           beforeMount={handleEditorWillMount}
@@ -374,38 +508,91 @@ function CodeEditor({ code, setCode, ws, users }: CodeEditorProps) {
         <div className={`w-0.5 h-full rounded-full transition-colors ${isDark ? 'bg-slate-700 group-hover:bg-slate-400' : 'bg-gray-300 group-hover:bg-gray-500'}`} />
       </div>
       <div style={{ width: `${100 - leftPercent}%` }} className={`border-2 ${isDark ? 'border-white' : 'border-gray-900'} rounded-lg overflow-hidden h-[85vh] relative`}>
-        {hasError && (
-          <div className='absolute top-2 right-2 z-10'>
-            <button 
-              onClick={handleSandpackReload}
-              className='bg-blue-500 hover:bg-blue-600 text-white px-4 py-2 rounded'
+        {showPreview ? (
+          <>
+            {hasError && (
+              <div className='absolute top-2 right-2 z-10'>
+                <button
+                  onClick={handleSandpackReload}
+                  className='bg-blue-500 hover:bg-blue-600 text-white px-4 py-2 rounded'
+                >
+                  Reload Preview
+                </button>
+              </div>
+            )}
+            <SandpackProvider
+              key={`${sandpackKey}-${language}`}
+              template={selectedLang.sandpackTemplate}
+              files={{
+                '/App.js': debouncedCode,
+              }}
+              theme={isDark ? 'dark' : 'light'}
+              options={{
+                externalResources: [],
+                bundlerURL: 'https://sandpack-bundler.codesandbox.io',
+                recompileMode: 'delayed',
+                recompileDelay: 300,
+                autoReload: true,
+              }}
+              style={{ height: '100%' }}
             >
-              Reload Preview
-            </button>
+              <SandpackPreview
+                style={{ height: '100%' }}
+                showOpenInCodeSandbox={false}
+                showRefreshButton={true}
+              />
+            </SandpackProvider>
+          </>
+        ) : (
+          <div className='flex flex-col h-full bg-[#1e1e1e] text-white font-mono text-sm'>
+            <div className='flex items-center justify-between px-4 py-2 bg-[#2d2d2d] border-b border-[#3e3e3e] flex-shrink-0'>
+              <span className='text-gray-400 text-xs uppercase tracking-wider'>Output</span>
+              <button
+                onClick={runCode}
+                disabled={isRunning}
+                className='flex items-center gap-1.5 px-3 py-1 bg-green-600 hover:bg-green-700 disabled:opacity-50 disabled:cursor-not-allowed text-white text-xs font-medium rounded transition-colors'
+              >
+                {isRunning ? (
+                  <>
+                    <svg className='animate-spin' xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' viewBox='0 0 24 24'>
+                      <circle className='opacity-25' cx='12' cy='12' r='10' stroke='currentColor' strokeWidth='4' />
+                      <path className='opacity-75' fill='currentColor' d='M4 12a8 8 0 018-8v8z' />
+                    </svg>
+                    Running...
+                  </>
+                ) : (
+                  <>
+                    <svg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='currentColor'>
+                      <polygon points='5,3 19,12 5,21' />
+                    </svg>
+                    Run
+                  </>
+                )}
+              </button>
+            </div>
+            <div className='flex-1 overflow-y-auto p-4'>
+              {runError && (
+                <p className='text-red-400'>{runError}</p>
+              )}
+              {runOutput && (
+                <>
+                  {runOutput.stdout && (
+                    <pre className='whitespace-pre-wrap text-gray-100'>{runOutput.stdout}</pre>
+                  )}
+                  {runOutput.stderr && (
+                    <pre className='whitespace-pre-wrap text-red-400 mt-2'>{runOutput.stderr}</pre>
+                  )}
+                  <p className={`mt-3 text-xs ${runOutput.code === 0 ? 'text-green-400' : 'text-red-400'}`}>
+                    exited with code {runOutput.code}
+                  </p>
+                </>
+              )}
+              {!runOutput && !runError && !isRunning && (
+                <p className='text-gray-500'>press Run to execute your code</p>
+              )}
+            </div>
           </div>
         )}
-        <SandpackProvider
-          key={sandpackKey}
-          template={'react'}
-          files={{
-            '/App.js': debouncedCode,
-          }}
-          theme={isDark ? 'dark' : 'light'}
-          options={{
-            externalResources: [],
-            bundlerURL: 'https://sandpack-bundler.codesandbox.io',
-            recompileMode: 'delayed',
-            recompileDelay: 300,
-            autoReload: true,
-          }}
-          style={{ height: '100%' }}
-        >
-          <SandpackPreview 
-            style={{ height: '100%' }}
-            showOpenInCodeSandbox={false}
-            showRefreshButton={true}
-          />
-        </SandpackProvider>
       </div>
     </div>
   );
diff --git a/frontend/src/components/room/RoomPage.tsx b/frontend/src/components/room/RoomPage.tsx
index c31e563..751bad2 100644
--- a/frontend/src/components/room/RoomPage.tsx
+++ b/frontend/src/components/room/RoomPage.tsx
@@ -1,16 +1,22 @@
-import { useParams, useNavigate } from 'react-router-dom';
+import { useParams, useNavigate, useLocation } from 'react-router-dom';
 import { useState, useEffect, useContext, useRef } from 'react';
 import { joinRoom, getRoomName } from '../../api/api';
 import EnterName from './EnterName';
-import CodeEditor from './CodeEditor';
+import CodeEditor, { type InterviewType } from './CodeEditor';
 import Popup from '../popup/Popup';
 import { DarkModeContext, UserContext } from '../../App';
-import { DEFAULT_CODE } from '../../util/templateContent';
+import { DEFAULT_CODE } from '../../util/reactTemplateContent';
 const WS_URL = import.meta.env.VITE_WS_URL || 'ws://localhost:7778';
 
-function RoomPage() {
+interface RoomPageProps {
+  interviewType?: InterviewType;
+}
+
+function RoomPage({ interviewType: propInterviewType }: RoomPageProps) {
   const { roomId } = useParams<{ roomId: string }>();
   const navigate = useNavigate();
+  const location = useLocation();
+  const interviewType: InterviewType = (location.state as { interviewType?: InterviewType })?.interviewType ?? propInterviewType ?? 'react';
   const { isDark } = useContext(DarkModeContext);
   const { userId } = useContext(UserContext);
   const [userName, setUserName] = useState('');
@@ -320,6 +326,8 @@ function RoomPage() {
         code={code}
         setCode={setCode}
         ws={ws}
+        roomId={roomId!}
+        interviewType={interviewType}
         users={users}
       />
       {/* Toast notifications */}
diff --git a/frontend/src/components/templates/TemplatesPage.tsx b/frontend/src/components/templates/TemplatesPage.tsx
index ae4bb5d..a0a622c 100644
--- a/frontend/src/components/templates/TemplatesPage.tsx
+++ b/frontend/src/components/templates/TemplatesPage.tsx
@@ -2,7 +2,7 @@ import { useContext } from 'react';
 import { useNavigate, useLocation } from 'react-router-dom';
 import { DarkModeContext, UserContext } from '../../App';
 import { createRoom } from '../../api/api';
-import { TEMPLATES, type Template } from '../../util/templateContent';
+import { TEMPLATES, type Template } from '../../util/reactTemplateContent';
 
 function TemplatesPage() {
   const { isDark } = useContext(DarkModeContext);
@@ -18,7 +18,7 @@ function TemplatesPage() {
 
   const handleSelectTemplate = async (template: Template) => {
     const finalRoomName = roomName || template.name;
-    const response = await createRoom(userId, userName, finalRoomName, template.code);
+    const response = await createRoom(userId, userName, finalRoomName, 'react', template.code);
     if (response.ok) {
       const roomId = response.data.roomId;
       const expiry = new Date().getTime() + (24 * 60 * 60 * 1000);
diff --git a/frontend/src/util/templateContent.example.ts b/frontend/src/util/reactTemplateContent.example.ts
similarity index 100%
rename from frontend/src/util/templateContent.example.ts
rename to frontend/src/util/reactTemplateContent.example.ts
diff --git a/go.mod b/go.mod
index a342fec..8aacf00 100644
--- a/go.mod
+++ b/go.mod
@@ -14,8 +14,9 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bytedance/sonic v1.14.0 // indirect
 	github.com/bytedance/sonic/loader v0.3.0 // indirect
-	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/cloudwego/base64x v0.1.6 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/gabriel-vasile/mimetype v1.4.9 // indirect
 	github.com/gin-contrib/sse v1.1.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
@@ -36,8 +37,10 @@ require (
 	github.com/prometheus/procfs v0.12.0 // indirect
 	github.com/quic-go/qpack v0.5.1 // indirect
 	github.com/quic-go/quic-go v0.54.0 // indirect
+	github.com/redis/go-redis/v9 v9.18.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.3.0 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/mock v0.5.0 // indirect
 	golang.org/x/arch v0.20.0 // indirect
 	golang.org/x/crypto v0.40.0 // indirect
diff --git a/go.sum b/go.sum
index 3949b0c..288351a 100644
--- a/go.sum
+++ b/go.sum
@@ -6,12 +6,16 @@ github.com/bytedance/sonic/loader v0.3.0 h1:dskwH8edlzNMctoruo8FPTJDF3vLtDT0sXZw
 github.com/bytedance/sonic/loader v0.3.0/go.mod h1:N8A3vUdtUebEY2/VQC0MyhYeKUFosQU6FxH2JmUe6VI=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cloudwego/base64x v0.1.6 h1:t11wG9AECkCDk5fMSoxmufanudBtJ+/HemLstXDLI2M=
 github.com/cloudwego/base64x v0.1.6/go.mod h1:OFcloc187FXDaYHvrNIjxSe8ncn0OOM8gEHfghB2IPU=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
 github.com/gabriel-vasile/mimetype v1.4.9 h1:5k+WDwEsD9eTLL8Tz3L0VnmVh9QxGjRmjBvAG7U/oYY=
 github.com/gabriel-vasile/mimetype v1.4.9/go.mod h1:WnSQhFKJuBlRyLiKohA/2DtIlPFAbguNaG7QCHcyGok=
 github.com/gin-contrib/cors v1.7.6 h1:3gQ8GMzs1Ylpf70y8bMw4fVpycXIeX1ZemuSQIsnQQY=
@@ -70,6 +74,8 @@ github.com/quic-go/qpack v0.5.1 h1:giqksBPnT/HDtZ6VhtFKgoLOWmlyo9Ei6u9PqzIMbhI=
 github.com/quic-go/qpack v0.5.1/go.mod h1:+PC4XFrEskIVkcLzpEkbLqq1uCoxPhQuvK5rH1ZgaEg=
 github.com/quic-go/quic-go v0.54.0 h1:6s1YB9QotYI6Ospeiguknbp2Znb/jZYjZLRXn9kMQBg=
 github.com/quic-go/quic-go v0.54.0/go.mod h1:e68ZEaCdyviluZmy44P6Iey98v/Wfz6HCjQEm+l8zTY=
+github.com/redis/go-redis/v9 v9.18.0 h1:pMkxYPkEbMPwRdenAzUNyFNrDgHx9U+DrBabWNfSRQs=
+github.com/redis/go-redis/v9 v9.18.0/go.mod h1:k3ufPphLU5YXwNTUcCRXGxUoF1fqxnhFQmscfkCoDA0=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -85,6 +91,8 @@ github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
 github.com/ugorji/go/codec v1.3.0 h1:Qd2W2sQawAfG8XSvzwhBeoGq71zXOC/Q1E9y/wUcsUA=
 github.com/ugorji/go/codec v1.3.0/go.mod h1:pRBVtBSKl77K30Bv8R2P+cLSGaTtex6fsA2Wjqmfxj4=
+go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
+go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 go.uber.org/mock v0.5.0 h1:KAMbZvZPyBPWgD14IrIQ38QCyjwpvVVV6K/bHl1IwQU=
 go.uber.org/mock v0.5.0/go.mod h1:ge71pBPLYDk7QIi1LupWxdAykm7KIEFchiOqd6z7qMM=
 golang.org/x/arch v0.20.0 h1:dx1zTU0MAE98U+TQ8BLl7XsJbgze2WnNKF/8tGp/Q6c=
diff --git a/handlers/execute.go b/handlers/execute.go
new file mode 100644
index 0000000..6dc5441
--- /dev/null
+++ b/handlers/execute.go
@@ -0,0 +1,40 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"goderpad/config"
+	"goderpad/execution"
+)
+
+type executeRequest struct {
+	Language string `json:"language"`
+	Code     string `json:"code"`
+}
+
+func ExecuteHandler(c *gin.Context) {
+	if !config.GetEnableCodeExecution() {
+		c.JSON(http.StatusOK, execution.Result{
+			Stdout: "",
+			Stderr: "code execution is disabled! to enable, set enable_code_execution: true in config/config.yml and restart the server.",
+			Code:   -1,
+		})
+		return
+	}
+
+	var req executeRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"ok": false, "error": "invalid request"})
+		return
+	}
+
+	result, err := execution.RunCode(req.Language, req.Code)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"ok": false, "error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, result)
+}
diff --git a/handlers/http.go b/handlers/http.go
index 2cff1db..1c00a23 100644
--- a/handlers/http.go
+++ b/handlers/http.go
@@ -19,7 +19,7 @@ func CreateRoomHandler(c *gin.Context) {
 		return
 	}
 
-	roomID, err := services.CreateRoom(req.UserID, req.Name, req.RoomName, req.InitialCode)
+	roomID, err := services.CreateRoom(req.UserID, req.Name, req.RoomName, req.Language, req.InitialCode)
 	if err != nil {
 		if errors.Is(err, models.ErrRoomExists) || errors.Is(err, models.ErrRoomNil) {
 			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
@@ -55,6 +55,7 @@ func JoinRoomHandler(c *gin.Context) {
 		"data": map[string]any{
 			"roomName": response["roomName"],
 			"document": response["document"],
+			"language": response["language"],
 			"users":    response["users"],
 		},
 	})
@@ -85,6 +86,32 @@ func GetRoomNameHandler(c *gin.Context) {
 	})
 }
 
+func SwitchLanguageHandler(c *gin.Context) {
+	var req models.SwitchLanguageRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request"})
+		return
+	}
+
+	document, err := services.SwitchLanguage(req.RoomID, req.Language)
+	if err != nil {
+		if errors.Is(err, models.ErrRoomNotFound) {
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusInternalServerError, gin.H{"ok": false, "error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"ok": true,
+		"data": map[string]any{
+			"document": document,
+			"language": req.Language,
+		},
+	})
+}
+
 func ValidateKeyHandler(c *gin.Context) {
 	apiKey := c.GetHeader("x-api-key")
 	if apiKey == "" {
diff --git a/handlers/ws.go b/handlers/ws.go
index 2bde599..d56bdf3 100644
--- a/handlers/ws.go
+++ b/handlers/ws.go
@@ -1,14 +1,19 @@
 package handlers
 
 import (
+	"context"
+	"fmt"
 	"log"
 	"net/http"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/gorilla/websocket"
 
+	"goderpad/config"
 	"goderpad/metrics"
 	"goderpad/models"
+	"goderpad/services"
 )
 
 var upgrader = websocket.Upgrader{
@@ -114,6 +119,44 @@ func readBroadcastsFromUser(user *models.User, room *models.Room) {
 				continue
 			}
 		}
+		if msg.Type == string(models.ExecuteRequestMessageType) {
+			if !config.GetEnableCodeExecution() {
+				user.Send <- models.BroadcastMessage{
+					UserID: user.UserID,
+					Type:   string(models.ExecuteResultMessageType),
+					Payload: map[string]any{
+						"userId": user.UserID,
+						"stdout": "",
+						"stderr": "code execution is disabled! to enable, set enable_code_execution: true in config/config.yml and restart the server.",
+						"code":   -1,
+					},
+				}
+				continue
+			}
+			language, _ := msg.Payload["language"].(string)
+			code, _ := msg.Payload["code"].(string)
+			jobID := fmt.Sprintf("%s:%s:%d", room.RoomID, user.UserID, time.Now().UnixNano())
+			job := models.ExecuteJob{
+				JobID:    jobID,
+				RoomID:   room.RoomID,
+				UserID:   user.UserID,
+				Language: language,
+				Code:     code,
+			}
+			if err := services.PublishJob(context.Background(), job); err != nil {
+				user.Send <- models.BroadcastMessage{
+					UserID: user.UserID,
+					Type:   string(models.ExecuteResultMessageType),
+					Payload: map[string]any{
+						"userId": user.UserID,
+						"stdout": "",
+						"stderr": "failed to queue execution: " + err.Error(),
+						"code":   -1,
+					},
+				}
+			}
+			continue
+		}
 		room.Broadcast <- msg
 	}
 }
diff --git a/models/http.go b/models/http.go
index 7595875..4242c24 100644
--- a/models/http.go
+++ b/models/http.go
@@ -4,6 +4,7 @@ type CreateRoomRequest struct {
 	UserID      string `json:"userId"`
 	Name        string `json:"name"`
 	RoomName    string `json:"roomName"`
+	Language    string `json:"language"`
 	InitialCode string `json:"initialCode"`
 }
 
@@ -12,3 +13,8 @@ type JoinRoomRequest struct {
 	Name   string `json:"name"`
 	RoomID string `json:"roomId"`
 }
+
+type SwitchLanguageRequest struct {
+	RoomID   string `json:"roomId"`
+	Language string `json:"language"`
+}
diff --git a/models/job.go b/models/job.go
new file mode 100644
index 0000000..96f85d8
--- /dev/null
+++ b/models/job.go
@@ -0,0 +1,18 @@
+package models
+
+type ExecuteJob struct {
+	JobID    string `json:"jobId"`
+	RoomID   string `json:"roomId"`
+	UserID   string `json:"userId"`
+	Language string `json:"language"`
+	Code     string `json:"code"`
+}
+
+type ExecuteResult struct {
+	JobID  string `json:"jobId"`
+	RoomID string `json:"roomId"`
+	UserID string `json:"userId"`
+	Stdout string `json:"stdout"`
+	Stderr string `json:"stderr"`
+	Code   int    `json:"code"`
+}
diff --git a/models/room.go b/models/room.go
index 1ee5d46..6caebb6 100644
--- a/models/room.go
+++ b/models/room.go
@@ -14,7 +14,8 @@ type Room struct {
 	RoomID    string                `json:"roomId"`
 	RoomName  string                `json:"roomName"`
 	CreatedAt time.Time             `json:"-"`
-	Document  string                `json:"document"`
+	Language  string                `json:"language"`
+	Documents map[string]string     `json:"documents"`
 	Users     map[string]*User      `json:"users"`
 	Broadcast chan BroadcastMessage `json:"-"`
 	done      chan struct{}         `json:"-"`
@@ -26,16 +27,19 @@ type Room struct {
 	saveDebounce *time.Timer `json:"-"`
 }
 
-func NewRoom(roomID, roomName, initialCode string) *Room {
-	document := utils.DEFAULT_CODE
+func NewRoom(roomID, roomName, language, initialCode string) *Room {
+	document := utils.DefaultCodeForLanguage(language)
 	if initialCode != "" {
 		document = initialCode
 	}
+	documents := make(map[string]string)
+	documents[language] = document
 	room := &Room{
 		RoomID:    roomID,
 		RoomName:  roomName,
 		CreatedAt: time.Now(),
-		Document:  document,
+		Language:  language,
+		Documents: documents,
 		Users:     make(map[string]*User),
 		done:      make(chan struct{}),
 		Broadcast: make(chan BroadcastMessage),
@@ -49,6 +53,23 @@ func (r *Room) Close() {
 	close(r.Broadcast)
 }
 
+func (r *Room) GetDocument() string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return r.Documents[r.Language]
+}
+
+func (r *Room) SwitchLanguage(language string) string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.Language = language
+	if doc, exists := r.Documents[language]; exists {
+		return doc
+	}
+	r.Documents[language] = utils.DefaultCodeForLanguage(language)
+	return r.Documents[language]
+}
+
 func (r *Room) AddUser(user *User) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
@@ -92,7 +113,7 @@ func (r *Room) BroadcastToUsers() {
 			r.mu.Lock()
 			if msg.Type == "code_update" {
 				if code, ok := msg.Payload["code"].(string); ok {
-					r.Document = code
+					r.Documents[r.Language] = code
 					r.dirty = true
 					r.scheduleSave()
 				}
@@ -133,7 +154,7 @@ func (r *Room) saveToFile() {
 	}
 
 	filePath := filepath.Join(dirPath, r.RoomName)
-	if err := os.WriteFile(filePath, []byte(r.Document), 0644); err != nil {
+	if err := os.WriteFile(filePath, []byte(r.Documents[r.Language]), 0644); err != nil {
 		metrics.DocumentSavesErrorsTotal.Inc()
 		return
 	}
diff --git a/models/ws.go b/models/ws.go
index 8e25300..ad41d3e 100644
--- a/models/ws.go
+++ b/models/ws.go
@@ -9,6 +9,8 @@ const (
 	CodeUpdateMessageType       MessageType = "code_update"
 	SelectionUpdateMessageType  MessageType = "selection_update"
 	VisibilityChangeMessageType MessageType = "visibility_change"
+	ExecuteRequestMessageType   MessageType = "execute_request"
+	ExecuteResultMessageType    MessageType = "execute_result"
 )
 
 type BroadcastMessage struct {
diff --git a/redisclient/client.go b/redisclient/client.go
new file mode 100644
index 0000000..e802fc8
--- /dev/null
+++ b/redisclient/client.go
@@ -0,0 +1,38 @@
+package redisclient
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"github.com/redis/go-redis/v9"
+
+	"goderpad/config"
+)
+
+var client *redis.Client
+
+func Init() error {
+	client = redis.NewClient(&redis.Options{
+		Addr:     config.GetRedisAddr(),
+		Password: config.GetRedisPassword(),
+		DB:       config.GetRedisDB(),
+	})
+
+	if err := client.Ping(context.Background()).Err(); err != nil {
+		return fmt.Errorf("failed to connect to redis: %w", err)
+	}
+
+	log.Printf("connected to redis at %s", config.GetRedisAddr())
+	return nil
+}
+
+func GetClient() *redis.Client {
+	return client
+}
+
+func Close() {
+	if client != nil {
+		client.Close()
+	}
+}
diff --git a/services/jobqueue.go b/services/jobqueue.go
new file mode 100644
index 0000000..a6cf882
--- /dev/null
+++ b/services/jobqueue.go
@@ -0,0 +1,128 @@
+package services
+
+import (
+	"context"
+	"encoding/json"
+	"log"
+	"os"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+
+	"goderpad/models"
+	"goderpad/redisclient"
+)
+
+const (
+	JobsStream    = "goderpad:jobs"
+	ResultsStream = "goderpad:results"
+	ServerGroup   = "server"
+)
+
+func serverConsumerName() string {
+	hostname, _ := os.Hostname()
+	return "server-" + hostname
+}
+
+// PublishJob adds an execution job to the Redis jobs stream.
+func PublishJob(ctx context.Context, job models.ExecuteJob) error {
+	data, err := json.Marshal(job)
+	if err != nil {
+		return err
+	}
+
+	return redisclient.GetClient().XAdd(ctx, &redis.XAddArgs{
+		Stream: JobsStream,
+		MaxLen: 1000,
+		Approx: true,
+		Values: map[string]interface{}{
+			"data": string(data),
+		},
+	}).Err()
+}
+
+// StartResultListener consumes execution results from Redis and routes them
+// back to the appropriate room's WebSocket connections.
+func StartResultListener(ctx context.Context) {
+	rdb := redisclient.GetClient()
+	consumer := serverConsumerName()
+
+	// Create consumer group, ignore error if it already exists
+	err := rdb.XGroupCreateMkStream(ctx, ResultsStream, ServerGroup, "0").Err()
+	if err != nil && err.Error() != "BUSYGROUP Consumer Group name already exists" {
+		log.Printf("warning: could not create results consumer group: %v", err)
+	}
+
+	log.Printf("result listener started (consumer=%s)", consumer)
+
+	for {
+		select {
+		case <-ctx.Done():
+			log.Println("result listener shutting down")
+			return
+		default:
+		}
+
+		streams, err := rdb.XReadGroup(ctx, &redis.XReadGroupArgs{
+			Group:    ServerGroup,
+			Consumer: consumer,
+			Streams:  []string{ResultsStream, ">"},
+			Count:    10,
+			Block:    5 * time.Second,
+		}).Result()
+
+		if err != nil {
+			if err == redis.Nil || ctx.Err() != nil {
+				continue
+			}
+			log.Printf("error reading results stream: %v", err)
+			time.Sleep(1 * time.Second)
+			continue
+		}
+
+		for _, stream := range streams {
+			for _, msg := range stream.Messages {
+				handleResultMessage(ctx, rdb, msg)
+			}
+		}
+	}
+}
+
+func handleResultMessage(ctx context.Context, rdb *redis.Client, msg redis.XMessage) {
+	data, ok := msg.Values["data"].(string)
+	if !ok {
+		log.Printf("invalid result message: %s", msg.ID)
+		rdb.XAck(ctx, ResultsStream, ServerGroup, msg.ID)
+		return
+	}
+
+	var result models.ExecuteResult
+	if err := json.Unmarshal([]byte(data), &result); err != nil {
+		log.Printf("failed to unmarshal result: %v", err)
+		rdb.XAck(ctx, ResultsStream, ServerGroup, msg.ID)
+		return
+	}
+
+	hub := models.GetHub()
+	room, exists := hub.GetRoom(result.RoomID)
+	if !exists {
+		log.Printf("result for unknown room %s, discarding", result.RoomID)
+		rdb.XAck(ctx, ResultsStream, ServerGroup, msg.ID)
+		return
+	}
+
+	// Send execute_result to ALL users in the room (including the one who triggered it).
+	// Using empty UserID so BroadcastToUsers won't skip anyone.
+	room.Broadcast <- models.BroadcastMessage{
+		UserID: "",
+		Type:   string(models.ExecuteResultMessageType),
+		Payload: map[string]any{
+			"userId": result.UserID,
+			"stdout": result.Stdout,
+			"stderr": result.Stderr,
+			"code":   result.Code,
+		},
+	}
+
+	rdb.XAck(ctx, ResultsStream, ServerGroup, msg.ID)
+}
diff --git a/services/room.go b/services/room.go
index d175652..b0dfb53 100644
--- a/services/room.go
+++ b/services/room.go
@@ -14,9 +14,9 @@ import (
 
 // CreateRoom creates a new room with the given details.
 // It does NOT add a user to the room, that is handled in the JoinRoom function.
-func CreateRoom(userID, name, roomName, initialCode string) (string, error) {
+func CreateRoom(userID, name, roomName, language, initialCode string) (string, error) {
 	roomID := utils.GenerateRoomCode()
-	room := models.NewRoom(roomID, roomName, initialCode)
+	room := models.NewRoom(roomID, roomName, language, initialCode)
 
 	hub := models.GetHub()
 	if err := hub.AddRoom(room); err != nil {
@@ -46,12 +46,23 @@ func JoinRoom(userID, name, roomID string) (map[string]any, error) {
 
 	response := map[string]any{
 		"roomName": room.RoomName,
-		"document": room.Document,
+		"document": room.GetDocument(),
+		"language": room.Language,
 		"users":    room.GetCurrentUsers(),
 	}
 	return response, nil
 }
 
+func SwitchLanguage(roomID, language string) (string, error) {
+	hub := models.GetHub()
+	room, exists := hub.GetRoom(roomID)
+	if !exists {
+		return "", models.ErrRoomNotFound
+	}
+	document := room.SwitchLanguage(language)
+	return document, nil
+}
+
 func GetRoomName(roomID string) (string, error) {
 	hub := models.GetHub()
 	room, exists := hub.GetRoom(roomID)
diff --git a/utils/defaultCode.go b/utils/defaultCode.go
index 3c2974c..1b05ec6 100644
--- a/utils/defaultCode.go
+++ b/utils/defaultCode.go
@@ -1,3 +1,29 @@
 package utils
 
-const DEFAULT_CODE = "import React from 'react';\n\nfunction App() {\n  return (\n    <div>\n      <h1>Hello, World!</h1>\n    </div>\n  );\n}\nexport default App;"
+const DEFAULT_REACT_CODE = "import React from 'react';\n\nfunction App() {\n  return (\n    <div>\n      <h1>Hello, World!</h1>\n    </div>\n  );\n}\nexport default App;"
+
+const DEFAULT_PYTHON_CODE = "def main():\n    print(\"Hello, World!\")\n main()"
+
+const DEFAULT_JAVA_CODE = "public class Main {\n    public static void main(String[] args) {\n        System.out.println(\"Hello, World!\");\n    }\n}"
+
+const DEFAULT_CPP_CODE = "#include <iostream>\n\nint main() {\n    std::cout << \"Hello, World!\" << std::endl;\n    return 0;\n}"
+
+const DEFAULT_JAVASCRIPT_CODE = "function main() {\n  console.log(\"Hello, World!\");\n}\n main()"
+
+// DEFAULT_CODE kept for backwards compatibility
+const DEFAULT_CODE = DEFAULT_REACT_CODE
+
+func DefaultCodeForLanguage(language string) string {
+	switch language {
+	case "python":
+		return DEFAULT_PYTHON_CODE
+	case "java":
+		return DEFAULT_JAVA_CODE
+	case "cpp":
+		return DEFAULT_CPP_CODE
+	case "javascript":
+		return DEFAULT_JAVASCRIPT_CODE
+	default: // "react" and anything unrecognised
+		return DEFAULT_REACT_CODE
+	}
+}