Technology

Technical write-ups on the tools behind building a product: what works, what it costs, and where it breaks on Hebrew.

• Digitally signing PDFs in Node.js: how it works and where it breaks

  ByteRange, CMS, PAdES levels B-T and B-LTA, RFC 3161 timestamps, where the private key should live, and why any edit after signing kills the signature. Verification code included.

• Generating PDFs in Node.js: ten approaches compared

  Puppeteer, Playwright, Gotenberg, PDFKit, pdf-lib, react-pdf, jsPDF, Typst, LibreOffice and hosted APIs. How each one works, what it weighs, and how it behaves with Hebrew and RTL text.

• Receipt scanning with a language model: what works, and how to catch an invented number

  OCR versus a vision model, schema-forced output, arithmetic checks that expose a fabricated field, building an eval on real receipts, cost per document, and what leaves your system.