The Resilience & Observability Stack

This article discusses building a production-ready FastAPI in 2026 by implementing the 'Contract-First' development approach, which includes three implicit promises: predictable errors, visible health, and self-healing systems. The article covers two pillars: Observability and Resilience, using tools like Structlog, Prometheus, Sentry, Rich, Tenacity, and SlowAPI. Engineers should install Rich tracebacks, configure Structlog for JSON logging, and use Prometheus to expose metrics. Additionally, they should fix Sentry to include HTTPException details.