systematic-debugging

Root-cause debugging enforces investigating the actual origin of a bug before attempting any fix, preventing random patches that waste time and create new bugs. It mandates evidence collection and reproduction before implementation.

Debug a failing test or production bug systematically through a four-phase workflow: investigate root cause, analyze patterns, test hypotheses, and implement the fix with a failing test, followed by an architectural review.

The best way to fix build errors under time pressure is following a disciplined phase-based diagnostic workflow that enforces order and validation, ensuring you explore causes and collect evidence before proposing any quick fixes.

TDD fits into the implementation phase of root-cause debugging by requiring a failing test that validates the fix before the code change is applied. This ensures the reproduction case is captured and the root cause is confirmed.

Use a phase-based debugging process when encountering any bug, test failure, unexpected behavior, or build failure — especially under time pressure when a quick fix seems obvious, or when a previous fix did not resolve the issue.

An architectural review follows the implementation phase to evaluate whether structural patterns contributed to the root cause, ensuring the fix integrates safely and preventing similar bugs from recurring in the wider system architecture.