Incremental Methodology

Each function completed through this process leaves behind two durable artifacts — working tests and inline documentation — neither of which existed before. Completing a legacy component through this disciplined methodology transforms it from an obstacle into a demonstration of sound engineering practice. Forcing deep understanding of a legacy codebase through tests and documentation advances the developer's own capabilities beyond what greenfield work provides. The effective approach to legacy code is deliberately slow and incremental, but guarantees that every step represents real forward progress.