How it works: Upload a PDF → drag signature/date/text fields onto it → send to signer via email → they sign with a link (no account needed) → you get the signed PDF with a full audit trail and verification certificate.
Tech stack: Next.js + FastAPI + PostgreSQL + PyMuPDF. PDFs are stamped server-side (image overlay, not AcroForm) so it works reliably on any PDF. Every signed document gets a QR code and cryptographic verification so you can prove it wasn't tampered with.
Also built 12 free PDF tools (merge, split, compress, watermark, etc.) that run entirely on the server with no file storage — processed and returned immediately.
Would love feedback on the signing UX and what features matter most for your use case.