MakeFaster: cut Lighthouse LCP ~73% cold / ~70% warm (6 kept experiments) - #1
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jjcm wants to merge 6 commits into
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MakeFaster: cut Lighthouse LCP ~73% cold / ~70% warm (6 kept experiments)#1jjcm wants to merge 6 commits into
jjcm wants to merge 6 commits into
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Co-authored-by: Jacob Miller <j@jjcm.org>
Co-authored-by: Jacob Miller <j@jjcm.org>
…mounts Co-authored-by: Jacob Miller <j@jjcm.org>
Co-authored-by: Jacob Miller <j@jjcm.org>
Co-authored-by: Jacob Miller <j@jjcm.org>
Co-authored-by: Jacob Miller <j@jjcm.org>
jjcm
marked this pull request as ready for review
August 26, 2026 00:16
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Summary
Experimental render-performance loop (MakeFaster) run against the production build of this fork, served locally. North star: Lighthouse LCP (v13.4.1, simulated mobile throttling, median of 3 runs per condition, cold + warm).
Kept changes (one commit each)
scripts/compress-build.jsruns afterreact-scripts buildand emits gzip + brotli siblings for the text assets inbuild/(vendor chunk 2,027 KB → 407 KB brotli). Any static host that serves compressed siblings picks them up (e.g. nginxgzip_static/brotli_static,http-server -g --brotli). Measured: −60.8% cold LCP.chart.js+moment(~206 KB raw) load via dynamic import only when a chart/scatter visualization actually renders; the home route never fetches them. −5.5% cold LCP.public/index.htmlpaints the app frame and the home intro paragraph (the LCP element) from static HTML+CSS before the bundle mounts; React replaces it on mount, and an inline script hides it on deep links. −8.7% cold LCP, warm FCP 3,176 → 755 ms.loadevent instead of an async<head>script, so it no longer competes with render-critical resources (the stub queue still records early events). −12.6% cold LCP.fonts.googleapis.comstylesheet +fonts.gstatic.comfetch with an inline@font-faceover a same-origin woff2 (one variable-width latin file covers weights 400/700). −11.4% cold LCP, cold FCP 3,116 → 759 ms.Tried and reverted (by the numbers)
loading="lazy"on markdown images (−0.7%, below the noise floor)font-display: swapalone (−0.7% — the web-font repaint forms a larger, later LCP candidate)Notes