Legacy-code maintenance
Problem
In legacy code, a small modification can depend on implicit rules, old integrations, or undocumented flows.
Analysis
Before editing, the affected path, entry points, dependencies, and ways to verify unchanged behavior are identified. Understanding the system is part of the work, not disposable preparation.
Intervention
Narrow changes, clear names, and available manual or automated checks are preferred. Where the context allows, decisions that reduce future uncertainty are documented as well.
Validation
The motivating case is checked and nearby paths are reviewed, especially those sharing data, queries, or business logic.
Result or learning
Learning: improving legacy code starts by reducing risk and increasing understanding, not merely by rewriting it.