Race Conditions

Overview

When outcome depends on timing, you have a race. Races are bugs waiting to happen.

Race conditions occur when correctness depends on the relative timing of events. They're insidious because they work most of the time, fail randomly, and are nearly impossible to reproduce.

When to Use

• Multiple async operations access shared state
• Database read-then-write patterns
• Concurrent API requests modify same resource
• "Works in development, fails in production"
• Intermittent bugs that can't be reproduced

The Iron Rule