Engineering Process
Build so the next change is cheap. Most of the work is not the first version — it is leaving the codebase in a state where the second one is easy.
01
Retrofitting is its own skill
Joining a codebase mid-life is not the same job as starting one. At XP Network the work was rebuilding existing surfaces to a new product direction without stopping the product, which needs a different sequence from a greenfield build.
See it in XP Network Web App →02
Introduce testing where there is none
A testing culture cannot be declared. It arrives one meaningful test at a time, on the paths that actually break, until the suite is worth trusting — which is how it went at XP Network.
See it in XP Network Web App →03
One system, many front doors
Shared schema first, surfaces second. Garaje runs six front ends against one backend, so a change to the model reaches every door at once instead of being reimplemented per app.
See it in Garaje →04
Build for the real room
Software meets the world at the least convenient moment. The XP Network mobile check-in had to work at a door, on venue wifi, with a queue behind it — which decides more about the implementation than the happy path ever does.
See it in XP Network Mobile →05
Say what went wrong
Every case study here carries what I got wrong and what I would fix. Writing that down is part of the process, not an epilogue to it: it is the only reliable way the next project inherits the lesson.
See it in QRmo →