SEC Reg CF Crowdfunding Backend

Context

A US fintech startup building an SEC Regulation CF investment crowdfunding platform needed its backend engineered to a regulatory standard. The system covers the full investment lifecycle — offerings, escrow, and the ledger — behind APIs consumed by a Next.js 16 front end.

The Hard Part

Reg CF money movement leaves no room for drift between what happened and what is recorded, so balances are never stored — they are derived from an immutable event stream, with escrow transitions locked behind a strict state machine.

What I Built

• Event-sourced ledger with 31 event types as the single source of financial truth
• 6-state escrow state machine governing how funds move through an offering
• 28-model Prisma schema on NestJS covering the full investment domain
• 30 documented API endpoints consumed by a Next.js 16 front end
• 248-test suite gating every change

Measured Results

Tech Stack