Rate-limiting

Implement per-user token budgets, tiered model access, request queuing, cost attribution, real-time dashboards, and anomaly detection to prevent AI bill shock.

Design API gateways for rate limiting, JWT auth, request aggregation, and versioning. Learn gateway vs service mesh and Kong vs cloud vendors.

Master Redis patterns: cache-aside vs write-through caching, distributed locks with Lua, sliding window rate limiters, pub/sub, sorted sets for leaderboards, Redis Streams, and memory management.