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$devvkit resources --research distributed-systems:-key-concepts-for-api-designers

Distributed Systems: Key Concepts for API Designers

4min
[distributed-systems][api][backend]

TL;DR: CAP theorem, eventual consistency, circuit breakers, and rate limiting are the core distributed systems concepts every API developer needs to understand.

Key findings
  • CAP theorem: A distributed system can guarantee at most two of Consistency, Availability, and Partition Tolerance. Partition tolerance is non-negotiable, so the real choice is CP vs AP.
  • Circuit breakers prevent cascading failures by stopping requests to a failing service, allowing it time to recover. Three states: closed (normal), open (failing), half-open (testing recovery).
  • Rate limiting and throttling protect services from overload. Token bucket algorithms allow natural burst behavior while maintaining average rate limits.
  • Idempotency keys enable safe retries in unreliable networks. The client generates a unique key, and the server deduplicates requests with the same key.
Why this matters for developers

Every API is part of a distributed system. Understanding CAP trade-offs, circuit breakers, rate limiting, and idempotency prevents production outages and data corruption.