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- System Design Foundations
- API Design at Scale
- Idempotency and safe retries
Idempotency and safe retries
Any request can be delivered twice. An idempotency key lets the second delivery return the first result instead of charging the card again.
- 8m
- Intermediate

Video by Software Developer Diaries · YouTube
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3 questions. Unlocks when you finish the video.
Overview
What this lesson covers
- Make write endpoints safe to retry
- Accept and store idempotency keys
- Retry with backoff and jitter, not in lockstep
This lesson sits in API Design at Scale, part of System Design Foundations. It assumes what came before it and leads directly into the next lesson in the module.
In this lesson you will:
- Make write endpoints safe to retry
- Accept and store idempotency keys
- Retry with backoff and jitter, not in lockstep
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