The index I added made the query slower, and the planner was right
Low selectivity plus random access beats a sequential scan only sometimes.
Engineering
Compose, Kotlin, and multiplatform work — the mechanism under the symptom.
229 posts
Rotating the key was the easy part
A committed secret is public the moment it is pushed. Deleting the line changes nothing.
Compose performance is one question asked in four places
Compose performance work reduces to knowing which of composition, layout and draw is being invalidated, and why. The diagnostic order matters more than any individual optimisation.
Drag-and-drop crosses app boundaries, which is why it isn't just a drag gesture
Compose's drag-and-drop moves ClipData between sources and targets, including across apps. Reordering a list is a different problem with a different solution, and conflating them is why reorder implementations get complicated.
Adding a parameter with a default broke the ABI
Source compatibility and binary compatibility are different guarantees, and a default argument preserves only the first.
Seven modules, seven copies of the same Gradle block
Copy-pasted build config drifts silently per module. A convention plugin makes the shared part shared.
An animation is state, and that is why it restarts
animate*AsState holds its value in the composition. A key change starts it over.
Your semantics tree is your test API and your accessibility API at once
A testTag is invisible to a screen reader. A contentDescription is not.
Focus is the input model you don't test until someone plugs in a keyboard
Compose's focus system handles keyboard, D-pad and accessibility navigation. The APIs are small, but modifier order matters, and a form with no focus handling is unusable on any device without a touchscreen.
Nested scroll is a negotiation, and there are four moments to intervene
NestedScrollConnection gives parents four chances to consume scroll deltas around a child. Choosing the wrong one is why collapsing headers collapse late, and why same-axis nesting misbehaves.
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.