The data API the whole desk reads
A distributor is only half the job — services need candles, history and quotes over an interface, with guarantees. This stage is the equity data service: REST and WebSocket, tiered caching, and a hard rule that a closed candle never changes underneath a consumer.
Built here.
- 01
A FastAPI service with REST and WebSocket surfaces for candles, quotes and instrument reference data across the NSE equity universe.
- 02
A candle-immutability guarantee: once an interval closes it is frozen, so two consumers asking the same question an hour apart get the same answer.
- 03
A tiered read path — local cache first, then the recent-tick store, then the warehouse, then the broker API — with an explicit fallback order rather than an accidental one.
- 04
A pooled broker-account layer so token limits and rate limits are handled centrally instead of being every caller's problem.
- 05
Symbol normalization and an instrument manager, because the same stock has a different identifier in every upstream dump.
- 06
Containerized deployment with health and cache-retention controls.
Failure modes.
- An upstream that is rate-limiting or unavailable, which degrades to the next tier instead of erroring the caller.
- Cold start at the open, when the warmup universe has to be loaded before the first request arrives.
- Cache growth, which is bounded by retention policy rather than by the disk filling up.
Research, dashboards and the order path all read one interface. When someone asks why a number differs between two screens, the answer is a cache tier, not a mystery.