Writing

Notes and essays on profiling and optimising interfaces that never stop updating. Steady-state performance, the part the load-time tools miss.

• 2026-06-19

  How to Profile a Real-Time UI

  A field playbook for profiling real-time UIs: read a Performance trace through three competing rates, input, compute and render, to find which mismatch is causing the jank, with the Chrome DevTools surface and the number for each, and what a healthy trace looks like.

  • performance
  • real-time
  • profiling
  • chrome-devtools
  • react

• 2026-06-12

  I Cancelled the Stale Request. The Render Still Lied.

  useEffect plus AbortController is the correct async pattern, and under load it still renders a state the data never made. Why cancellation is not coherence, and the one invariant that fixes it.

  • react
  • async
  • concurrency
  • state-management
  • real-time

• 2026-06-05

  The Animation Wasn't Where the Time Went

  A chart redraws at 5 Hz while its y-axis rescales. Animating the rescale as a composited transform, instead of re-rendering every frame, cut main-thread work by roughly two-thirds. The costs I braced for never fired. The redraw itself dominated.

  • performance
  • react
  • web-animations-api
  • svg
  • rendering