Glossary term
What is Race condition? Meaning for developers
In System Design
A bug where the result depends on the timing of concurrent actions. Example: Two people booking the last seat at the same moment.
Learn it properly · System DesignLesson 4: Processes, Threads & Concurrency for Backend EngineersMost backend work is waiting. How one server juggles thousands of requests — processes, threads, event loops and lightweight threads — and the race conditions, deadlocks and pool limits that appear the moment it does.In Scenario Debugging
A bug where the result depends on which async job finishes first. For example, an old response replaces a newer one.
Learn it properly · Scenario DebuggingLesson 5: Duplicate Requests, Race Conditions and Stale ResponsesStrict Mode running effects twice, double-click submits, responses that arrive in the wrong order, AbortController, removing duplicate requests, and idempotency keys on the server.In React in Depth
A bug where the result depends on which of two things finishes first, such as an old slow request arriving after a newer one and overwriting it.
Learn it properly · React in DepthLesson 5: Data Fetching, Caching and Server Statefetch in effects and its bugs, race conditions, loading and error states, TanStack Query ideas, and Suspense with use().