emptiness is not correctness
Two defects in the same period, and they share a shape. Both returned success. Neither raised an error. Both produced a surface that simply had nothing on it.
field notes
Short notes from real engineering work: one decision, one incident, one reversal at a time. Each one names the shape of the problem, the tension that made it hard, the decision, and what it cost. The internals stay out — the codename is the hint.
If you have five minutes rather than an afternoon: the three case studies condense this material to one problem, one decision and what the decision cost. The notes below are the record those studies cite — and the projects the codenames belong to are on the front page.
Two defects in the same period, and they share a shape. Both returned success. Neither raised an error. Both produced a surface that simply had nothing on it.
A design said orders keep their reference to the area they were priced against. The code agreed. The store did not, and nobody found out for several changes.
Serving many independent businesses from one store gives you a choice about where isolation lives. It can live in every query, politely: each read filters for the business it is serving. That works exactly as long as every author, on every…
On a platform shared by many independent businesses, the data shape is not a private implementation detail. Every surface, every workstream and every future feature reads it. So a schema change is a contract change, and the hard part is not…
method
Not a changelog entry and not a repository summary. One decision, one incident, one reversal, or one hard-won invariant — the thing an engineer would tell you at a whiteboard.
Prefer records with dates and root causes? Those are on incidents. Live numbers are on stats.