3E

3e is a fintech platform that reimagines money by turning gold into a productive asset. Investors grow their wealth while everyday users pay for goods and services online.

What we did

• Built the Node.js backend from scratch — over 100,000 lines — powering P2P transfers, QR-code payments, a marketplace, a real-estate portal, a donation tool and a WordPress plugin.
• Integrated four payment gateways: Fintecture, Stripe, GoCardless and Wise.
• Implemented end-to-end encryption with Diffie–Hellman key exchange for secure data exchanges.
• Wrote the VAPID (web push) and S3 protocols from scratch, with strict CSP compatibility.
• Set up continuous integration with Gitea to keep code quality high.
• Migrated the front end from React to HTMX, letting a small team maintain and scale a large codebase efficiently.
• Mentored two interns along the way.