A place for code I want to explain, mistakes worth remembering, and the occasional story from my life.
MySQL 2 min read
A tenant's invoice list filters by tenant, filters by status, and orders by creation time. Adding separate indexes to every column is not automatically the best answer. Start with...
MySQL 2 min read
An application locks a row, reads its value, ends the transaction, and only then makes the update. The lock no longer protects the decision. Another request can change the row betw...
MySQL 2 min read
Two requests try to reserve the last item. A separate SELECT followed by an unconditional UPDATE lets both requests make a decision from the same old stock value. For a simple decr...
Laravel 2 min read
A test asserts that a notification was sent, but the customer still receives nothing because the notification routes to a different channel. Notification dispatch, channel selectio...
Laravel 2 min read
A publication test passes most days but fails near midnight. The test depends on the actual wall clock instead of stating the exact instant it wants to examine. Freeze time and tes...
Laravel 2 min read
A new checkout boots only after someone copies a private production environment file. That is a sign the configuration contract is incomplete. .env.example should describe required...
Laravel 2 min read
A database migration changes a column while requests still use the old shape. Maintenance mode can reduce exposure during a short incompatible release, but it is not a substitute f...
Laravel 2 min read
A page feels slow, so the first proposal is to add Redis. Before introducing another system, measure whether the request performs one slow query, hundreds of small queries, or spen...
Laravel 2 min read
A customer is soft-deleted, then a new customer tries to reuse the same external code. The form says the code is available, but the database rejects the insert. Soft deletion hides...
