CodeIt: A Real-Time Collaborative Code Editor for Multi-user Programming

Real-time collaborative code editors have become essential for remote software development, online education, and distributed teamwork. Existing platforms such as Cloud9 IDE, Saros, Collabode, Codeshare.io, and JSFiddle introduced early collaboration features but suffer from scalability issues, limited multi-file management, and lack of integrated execution or AI support. Advanced editors like Replit and VS Code Live Share address some of these challenges but often require heavy setup or fail to unify execution, communication, and intelligent coding assistance in a lightweight browser-based system. Research on concurrency control mechanisms such as Operational Transformation (OT) and Conflict-Free Replicated Data Types (CRDTs) has improved synchronization and consistency, yet their complexity limits adoption in practical implementations. To address these gaps, this paper presents CodeIt, a web-based collaborative coding platform that integrates synchronized multi file editing, secure multi-language execution via Piston API, AI-assisted code generation, real-time chat, presence indicators, and a collaborative whiteboard. Built with React, TypeScript, Node.js, Express, and Socket.IO, the system ensures low-latency synchronization, scalability, and reliable updates through a CI/CD pipeline. Performance evaluation demonstrated stable responsiveness under concurrent usage, validating its robustness. By unifying editing, execution, and intelligent assistance, CodeIt advances collaborative programming for education, coding interviews, hackathons, and distributed teams.