
Fintech platforms
A ledger that disagrees with the bank by a penny is an incident, not a bug. We build the money side of the product: books that balance by construction, payment flows that survive being retried, and reconciliation an auditor can follow without you in the room.
- Immutable double-entry ledgers. Balances are derived from entries rather than stored and then updated.
- Idempotency keys and replayable event logs, so a retry across a PSP boundary cannot charge someone twice.
- Open Banking and PSD2 integrations, including the SCA and 3DS2 step-up flows nobody enjoys building.
- Stripe
- Adyen
- TrueLayer
- Plaid
- Postgres
- Kafka
- Temporal
- Go
- TypeScript
- Decimal arithmetic







