error-handling

For FastAPI and Express error handling, this approach provides framework-aware error responses, structured logging, and domain-specific exceptions to ensure consistent API error propagation and recovery across both web frameworks.

Implementing retry policies and circuit breakers for API errors involves classifying Transient errors for automatic retry with backoff, while applying circuit breaker patterns to prevent cascading failures in Python and TypeScript services.

A domain-specific exception hierarchy should classify errors into Transient, Operational, and Fatal tiers, guiding whether to retry, request user action, or escalate, ensuring structured logging and clear recovery across your application.

Yes, this error handling approach works for library and API service development by providing a standardized error contract, applying consistent exception hierarchies, retry policies, and user-friendly messages across Python and TypeScript projects.

Use fatal error classification when errors require system escalation, and operational classification when errors require user action. Transient errors trigger retry logic, ensuring appropriate recovery paths within your domain-specific exception hierarchy.