Dev Hive - Interview in real-time, code in sync

DevHive is a live collaborative code editor with built-in video calling. Run mock interviews, pair-program with your team, or grind DSA with friends — all face-to-face in one room.

Live Demo:

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Features

• Real-Time Code Collaboration — Monaco Editor synced live across all room participants via WebSocket
• Video & Audio Calling — LiveKit-powered WebRTC integration directly inside coding rooms
• WebSocket Messaging — STOMP over SockJS for bi-directional client-server communication
• Redis Write-Through Cache — live code/language updates hit Redis first, avoiding DB writes on every keystroke
• Scheduled DB Sync — background cron job (every 30s) persists cached Redis code back to the database
• Redis Pub/Sub Broadcasting — decouples publisher/subscriber for horizontally scalable, multi-instance WebSocket delivery
• Collision-Safe Room IDs — auto-generated unique room IDs with retry logic on conflict
• Concurrency-Safe Joins — pessimistic locking prevents race conditions when multiple users join simultaneously
• Reconnect Handling — rejoining users get re-synced state (USER_REJOIN) instead of duplicate participant entries
• Live Room Events — real-time broadcasts for user joined, left, rejoined, and room closed
• JWT Authentication — short-lived access tokens + long-lived refresh tokens (6 months) in HTTP-only cookies
• Role-Based LiveKit Tokens — per-user JWT tokens with admin grants for room owners
• Automatic Call Lifecycle Management — LiveKit room auto-created on call start, cleaned up on room end, participants auto-removed on leave
• Cache-Aside Fallback — graceful handling and logging of Redis cache misses with DB fallback
• Global Exception Handling — custom exceptions (ResourceNotFoundException, RoomNotAvailableException, AccessDeniedException) for consistent error responses
• Modular Service Architecture — clean separation across Room, User, LiveKit, and Redis services

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Tech Stack

Layer	Technology
Frontend	React, Vite, TailwindCSS
Code Editor	Monaco Editor (@monaco-editor/react)
WebSocket Client	SockJS + STOMP.js (@stomp/stompjs)
Video Calling	WebRTC (SFU topology) via LiveKit
Backend	Spring Boot
Real-time	WebSocket + STOMP
Cache / Pub-Sub	Redis
Database	PostgreSQL (Spring Data JPA)
Auth	JWT + Refresh Token (HttpOnly Cookie)

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Architecture

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API Reference

Auth — /auth

Method	Endpoint	Description
POST	/auth/signup	Register a new user
POST	/auth/login	Login; sets HttpOnly refresh token cookie
POST	/auth/refresh	Rotate access + refresh token
POST	/auth/logout	Revoke token + clear cookie

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Rooms — /rooms

Method	Endpoint	Description
POST	/rooms	Create a room (caller becomes OWNER)
POST	/rooms/{roomId}/join	Join as EDITOR
GET	/rooms/{roomId}	Get room info (live code from Redis if available)
DELETE	/rooms/{roomId}/end	Owner ends room; final Redis → DB sync
DELETE	/rooms/{roomId}/leave	Participant leaves room

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WebSocket

Direction	Destination	Description
Client → Server	/app/code-update/{roomId}	Send a code change; cached in Redis (ROOM_CODE_KEY, TTL via ROOM_TTL_HOURS) and republished
Client → Server	/app/lang-update/{roomId}	Change the room's active language; persisted via RoomService.langUpdate and republished
Server → Client	/topic/room/{roomId}	Receive code updates, language updates, join/leave events, video call events, room-end signal

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LiveKit — /livekit

Method	Endpoint	Description
POST	/livekit/token/{roomId}	Validates membership and returns a LiveKit access token for the caller to join the room's video call
POST	/livekit/start/{roomId}	Validates membership, creates the LiveKit room, returns the initiator's token, and broadcasts a VC_STARTED event to /topic/room/{roomId}

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Running Locally

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