REST API
FX Aggregation Service
RateWatch
FastAPI service that aggregates FX rates from multiple providers, computes a consensus value, serves live data from Redis cache, and persists historical snapshots to SQL.
Tech Stack
- FastAPI
- Redis Cache
- SQLAlchemy
- Alembic
Overview
RateWatch solves a common fintech problem: FX rates vary across providers. This service aggregates them, computes a weighted consensus, and serves the result with sub-millisecond latency from Redis.
Architecture
The system is built around three layers: an aggregation layer that polls providers on a schedule, a consensus engine that computes the weighted average, and a serving layer that reads from Redis cache.
Key Endpoints
GET /rates/{currency_pair}— live rate from cacheGET /rates/{currency_pair}/history— historical snapshots from SQLPOST /rates/refresh— manually trigger provider polling
