The index I added made the query slower, and the planner was right
Low selectivity plus random access beats a sequential scan only sometimes.
practices
42 posts
Rotating the key was the easy part
A committed secret is public the moment it is pushed. Deleting the line changes nothing.
The null that meant three different things
Not-yet-loaded, absent, and explicitly-cleared share one representation, and the UI has to guess.
Six weeks of optimisation, and the fix was two lines
Profiling found the hot function. The hot function was called a thousand times for one reason.
The health check that returned 200 while the service was useless
Proving the process is running keeps a broken instance in the load balancer.
The queue had no maximum, so the failure was memory and not latency
An unbounded buffer converts a throughput problem into an out-of-memory crash.
Offset pagination loses rows while you read, and the user never knows
An insert on page 1 shifts every later offset. A keyset cursor is data, not a position.
The webhook that arrived twice, and the order that shipped twice
At-least-once is the contract every provider offers. Your handler is where exactly-once gets built.
Your prompt is a config file, and it needs the same discipline
Untracked prompt edits are untracked behaviour changes.
The interface with one implementation, and the three years it cost
An abstraction written for a second implementation that never arrived is pure indirection.
The architecture decision nobody wrote down, re-litigated four times
Without the rejected options and the reason, every new engineer re-opens the question.
We shipped it, measured it, and deleted it eleven weeks later
Deciding the success metric before building is what makes deletion possible afterwards.