How should errors propagate across the layers of an application?

• A. Propagate errors with meaningful context and avoid leaking implementation details to higher layers
• B. Let errors bubble up with no context
• C. Translate all errors to a single generic message
• D. Catch and swallow errors

Answer: (A)

Errors should be propagated across layers with meaningful context while keeping abstraction boundaries intact. When a lower layer fails, carry forward a structured error that conveys what went wrong in a way the next layer can act on, but avoid leaking internal details like database schemas, SQL, or implementation specifics. For example, a data access failure can map to a domain-level error such as DataUnavailable or ExternalResourceError, possibly with an error code and a user-friendly message for the caller, while preserving full details in logs for debugging. This preserves security and encapsulation, enables consistent handling (retries, fallbacks, user feedback), and makes debugging easier because the cause is clear without exposing internals.

Letting errors bubble up with no context leaves higher layers powerless to respond appropriately. Translating everything to a single generic message robs downstream layers of actionable information and hurts both user experience and troubleshooting. Catching and swallowing errors hides problems and can lead to inconsistent states or later, harder failures.