Performance

The big win is architectural: one event loop, plugins registered once, page cache in core. On top of that, Tools → Performance suite writes gzip and browser-cache env vars and restarts via tmp/restart.txt on Passenger/Plesk.

Gzip#

JF_GZIP_ENABLED, JF_GZIP_LEVEL (1–9), JF_GZIP_MIN_BYTES. Compresses HTML, JSON, CSS, JS above the minimum size.

Browser cache#

JF_BROWSER_CACHE_ENABLED, JF_BROWSER_CACHE_HTML_MAX_AGE (default 60s), JF_BROWSER_CACHE_STATIC_MAX_AGE (default 86400s), JF_BROWSER_CACHE_SWR (stale-while-revalidate, default 300s).

Only the code a page uses#

From Justflows 0.4.1, a public page gets the menu, notice, sign-in, animation, and interactive-block scripts only when it contains that markup, so a plain page loads about 1 KB of core script instead of 8 KB, and the math stylesheet loads only on pages with a formula. Only the colour-scheme script runs before the page shows. Core scripts, theme.css, and theme.js use content-versioned URLs that browsers cache for good, so a repeat visit makes no revalidation requests, and theme.js is left out when the theme has no scripts.

Themes and plugins can do the same: assets.blocks loads files only on pages that render a given block, and assets.markup (plugins) only on pages that contain given markup. See Themes and Plugins.

The admin loads each screen the first time you open it, and the page builder, math formulas, and animations load only with the screens that use them. Opening the dashboard downloads about 154 KB of compressed JavaScript in 5 requests instead of 546 KB in 10, and the screen keeps its server-rendered content while the rest loads.

Admin APIs#

/api/performance/settings|stats|clear|stats/reset (administrator), alongside /api/cache/*. Saving settings from Tools is the supported UI. When saving restarts the app, Node's own flags (a TypeScript loader, --env-file, a heap size) are kept, except debugger and watch flags.