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DevFlow

A real-time collaborative code editor with syntax highlighting, live cursors, and integrated PR-style reviews.

Next.jsWebSocketsPostgreSQLMonaco EditorSupabase

Overview

DevFlow lets distributed teams write and review code together in real time. Think Figma — but for code editors. Multiple cursors, inline comments, and instant presence indicators make async collaboration feel synchronous.

Architecture

The app is built on Next.js App Router with Supabase Realtime handling live collaboration and a Postgres database for persisting sessions and reviews.

Key Features

  • Live cursors — see every collaborator's position as they type
  • Syntax highlighting — Powered by Monaco Editor, the engine behind VS Code
  • Inline reviews — Comment on specific lines without leaving the editor
  • Session history — Replay any editing session frame-by-frame

Challenges

Getting Monaco Editor to behave inside a Next.js SSR environment required dynamic imports and careful hydration handling. The OT (Operational Transform) algorithm for conflict resolution was the most intellectually demanding part of the project.

Results

Reduced async code-review round-trips by ~65% in early user testing with three remote teams.