Concurrency Patterns for Code Review

Overview

Concurrency bugs are among the hardest to reproduce: they appear non-deterministically, are invisible in unit tests, and can cause data corruption in production. Use this guide during code review to catch concurrency hazards before they ship.

When to Use

• Reviewing code that accesses shared state from multiple threads or coroutines
• Reviewing async/await code for hidden bottlenecks or error-swallowing
• Evaluating background task queues, worker pools, or message-passing systems
• Code touching databases, caches, or files from concurrent request handlers

Quick Reference