Lumen started as a personal frustration: every résumé builder forces a layout, a font, a brand. I wanted markdown in, PDF out, with templates I could actually fork.
The editor is monaco-powered with live PDF preview rendered server-side via headless Chromium. Templates are React Server Components compiled to print-ready CSS.
Shipped in 6 weeks, currently used by ~1.2k engineers a month. Source-available on GitHub.