Refactoring: Improving the Design of Existing Code

Why this matters here

Fowler’s Refactoring shows how design can improve continuously and how change-coupling and fragility patterns appear as codebases evolve. Coupling takes those patterns as a definitional hinge: some dependency is necessary, but hidden, fragile, constantly shifting dependencies turn small edits into system-wide breaks and then into organizational drag. The source is a craft of change; the book asks when teams spend more energy coordinating around fragility than improving the system itself.