Debugging: 9 Indispensable Rules
Central idea
Debugging becomes systematic when you replace guesses with reproducible evidence and narrow the search space one fact at a time.
Summary
Most debugging time is lost by acting before understanding. First reproduce the failure, observe the real system and environment, and collect facts without forcing them into your initial theory. Divide the system to isolate where correct behavior becomes incorrect. Change one variable at a time and keep an audit trail. Recheck assumptions, seek a fresh perspective when stuck, and verify the repair under the original failure conditions. The goal is not a plausible explanation; it is evidence that identifies the cause and proves the fix.
Key ideas
Make it fail reliably
A stable reproduction turns a mysterious report into an experiment you can repeat.
Divide and conquer
Find the boundary where good state becomes bad instead of inspecting every component at once.
Prove, do not assume
Validate inputs, versions, configuration, timing, and the final fix with direct observation.
A disciplined sequence
Reproduce.
Observe and understand.
Narrow the search space.
Test one hypothesis.
Prove the repair.
Why it matters now
AI is useful for generating hypotheses, but it can also produce confident stories. A rigorous evidence loop keeps debugging grounded in the actual system.
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