Backend Engineering · 3 min read
Idempotency keys in APIs: preventing duplicate charges and orders
Retries are unavoidable on real networks. How to implement idempotency keys in an API: storage, concurrency, payload validation and expiry.
Backend Engineering
APIs, databases, messaging and reliability in backend services.
- Backend Engineering · 3 min read
Zero-downtime migrations in PostgreSQL
A seemingly simple migration can lock an entire table in production. How to avoid long locks, use expand/contract, and add indexes and constraints safely.