Case study · 01 / 03· Fintech
Vault Ledger
Compliance-grade transaction reconciliation across multi-region banks.
Year2026
ClientConceptual study
RoleArchitecture & design
CategoryFintech
Fintech01 / 03
The challenge
Reconciling transactions across four payment processors with no single source of truth — and a quarterly compliance audit already on the calendar.
The execution
We built a unified ledger of record on FastAPI + PostgreSQL with transactional integrity guaranteed at the database level. Every event — transaction, refund, reversal — flows through a single audit trail with cryptographic signatures. The Next.js dashboard gives ops a live view; the compliance API exports regulator-ready evidence in one click.
The stack
What's under the hood.
Frontend
Next.jsTypeScriptTailwind
Backend
FastAPIPostgreSQLRedis
Infrastructure
CoolifyDockerMulti-region
The result
Outcomes that actually shipped.
30 daysGo-live
99.9%Uptime
4 providersIntegrated
See it live
Production deployment, access on request.