# Product & Requirements > Selected Engineer ApS work demonstrating Product & Requirements — the achievements that prove it. - [Built the payments and entitlements layer — Stripe alongside Apple and Google in‑app purchase — gating the directory, search and export through an 11‑table access model checked on the server.](https://platform.engineer.company/portfolio/built-the-payments-and-entitlements-layer-96/) - [Built company ownership claims end to end — a user claims a company, an administrator adjudicates, and an approval rewrites the authorization graph that decides who is allowed to edit what.](https://platform.engineer.company/portfolio/built-company-ownership-claims-end-to-end-103/)