TL;DR I had a 2. 1 MB initial JavaScript bundle and a Lighthouse performance score of 41 on mid-range Android. I used Claude Code as a measurement-driven "perf detective" instead of asking it to "make the app faster," and got the bundle down to 890 KB in about four working sessions.
Source: [Dev.to](https://dev.to/yureki_lab/how-i-cut-a-21-mb-javascript-bundle-to-890-kb-with-claude-code-2a0p)