My app is an Electron desktop for Claude Code: glass windows with backdrop-filter blur, a WebGL rain background, a few terminals. One day I wrote in my own bug list: "If I leave it running for a while, it gets really slow."

"Slow after a while" sounds like a memory leak. I was so sure that I nearly went looking for one. Then I measured first.

The measurement

One Claude Code session working in a terminal, the app in front. Numbers are CPU time per process, as a percentage of one core:

Version GPU process Renderer

installed 1.9 131 % 30 %

Memory was flat. Main process around 110 MB, renderer heap around 20 MB, no growth. No leak.

What actually happened: the laptop (integrated Intel graphics) got hot and throttled after a few minutes.…