Rate limiting you can prove: a machine-checked, fleet-size-independent overshoot bound on one small core — pure-function algorithms, one atomic store across in-memory/Redis/Postgres (proven bit-identical), a 169ns sync API, and provable two-tier leasing (
NestJS-first rate limiter module with pluggable strategies and stores.
gRPC service door for ThrottleKit — run the rate-limiting core as a network service for polyglot clients.