Why Sequence Diagrams Should Be Living Documentation

How to Turn Sequence Diagrams into Living Change Logs Your sequence diagrams are lying to you. That architecture diagram from six months ago? It shows three services talking to each other, but the code now has five, and two of them weren't even planned when someone drew those boxes and arrows. Static diagrams decay the moment you commit them. But sequence diagrams stored as code and updated through your PR workflow become something more powerful: a living change log that tracks how your system actually evolves. This guide covers how to store diagrams in version control, integrate updates into your review process, and build the habits that keep documentation accurate as your codebase grows. Why Static Sequence Diagrams Fail Engineering Teams Sequence diagrams visually map component interactions over time, making them ideal for documenting system evolution and onboarding new engineers. But here's the catch: most teams create diagrams during initial design, store them in wikis, and never