A self-hosted, real-time collaborative code editor with sandboxed code execution — built to explore CRDT-based sync and container orchestration end to end.

Why I built it: I started this while helping a friend prep for technical interviews. We couldn't find an environment where we could actually collaborate on code and compile it together in the same editor, so I built one.

• Engineering a real-time collaborative code editor with zero document conflicts by architecting a split backend, utilizing Node for native JavaScript Yjs CRDT synchronization and Spring Boot (Java) for durable persistence.
• Optimized PostgreSQL database load for live documents by designing a write-back persistence model that uses shared in-flight promises to deduplicate cache misses and debounce timers for state flushing.
• Secured untrusted code execution while capping worst-case server compute by orchestrating network-isolated, memory-capped Docker sandboxes managed through a bounded Java thread pool.
• Delivered anonymous session tracking for collaborative code workspaces using server-issued HttpOnly cookies and idempotent database upserts, allowing users to retain history without forced authentication.