Why Defining Requirements Before Writing Code Saves Costly Rework Later

Software engineer Anton argues that the timing of requirement definition determines how expensive a change becomes later in development. Before a contract or schema is declared, altering a requirement means editing a single document with no downstream impact. Once code, tests, and documentation are generated from that contract, a single-clause change must be coordinated across five or more artefacts simultaneously. An internal audit of one service tree on August 13, 2026, uncovered 44 duplicate implementations of just four database-reading patterns, largely because no shared standard had ever been formally stated. Consolidating those duplicates required 40 separate file-level changes, illustrating how an unstated requirement silently multiplies future maintenance work.