Principle: Fail fast and loud

Silent failures propagate through systems, making bugs harder to find. An error in one component surfaces as a mysterious symptom in another.

Design systems to fail immediately and visibly at the point of error:

1. Validate inputs at system boundaries, reject invalid data immediately
2. Use assertions for impossible states — crash rather than continue with corrupted data
3. Never swallow exceptions silently — log them at minimum, crash if appropriate
4. Return errors, don't hide them behind default values
5. In development: crash on warnings. In production: log and alert

Examples:

• Don't return empty array on error — throw or return Result type
• Don't default to 0 when a number is missing — make it required
• Don't silently skip invalid records — report them
• Assert invariants: if a list should never be empty, assert it

The further an error propagates from its source, the harder it is to debug. Failing fast keeps the error close to its cause.