Tokenized Investment Platform — Escrow & Ledger

Context

A fintech startup building an investment platform where holdings are issued and tracked as tokenized positions rather than plain database balances. The backend covers campaigns, escrow, an event-sourced ledger, on-chain settlement, and the compliance surface around all of it. The work has run across multiple milestones and is ongoing.

The Hard Part

Money and ownership have to agree at every moment. Positions are reconciled against issued supply, and escrow only moves through a state machine with optimistic locking and idempotent operations — so a partial release, a retry, or a failed settlement can never leave the ledger and the holder register disagreeing.

What I Built

• Event-sourced ledger spanning 54 event types as the record of financial truth
• 6-state escrow state machine with optimistic locking and idempotent operations
• Securities tokenization: issuance planning, mint authorization, and on-chain settlement
• Holder positions with lockup and freeze handling, reconciled against issued supply
• Two-tier role-based access control across 15 roles with per-action permission checks
• NestJS and Prisma backend behind a Next.js 16 and React 19 front end

Measured Results

“Financial-grade integrity… serializable transactions, idempotency, and audit-safe design patterns.”

Tech Stack