Systematic Debugging — Root Cause First

Iron Law

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST.

If you're about to change code to "try something," STOP. Investigate first.

The 4 Phases

Phase 1: Root Cause Investigation

1. Read the error — Read the FULL error message, stack trace, and logs. Not just the first line.

2. Reproduce — Can you make the error happen consistently? If not, gather more data before changing anything.