Find the Real Bug

The most common failure mode in debugging is treating the symptom as the bug. Wrapping a NullPointerException in try/catch makes it go away — and ships the bug. This skill enforces the discipline of finding the actual cause.

When to use

• Failing test, especially intermittent.
• Production error spike.
• User report of "weird" behavior with no obvious trigger.
• Metric regression (latency, error rate, cost) of unknown origin.
• Code review where you're tempted to "just add a null check."

When NOT to use

• You already know the cause and the fix is mechanical (e.g. typo, missed import).
• Time-critical hotfix where root cause analysis happens after the bleed stops — but commit to the post-mortem.

The five questions (answer in order)