01
HSM-backed key management
Hardware-rooted signing across three regions, with quorum approval flows for every withdrawal. Operational keys rotate quarterly; cold reserves move only with a physical-presence ceremony.
Crypto · Infrastructure
End-to-end settlement infrastructure for a stable-coin issuer.
Transaction, custody and reconciliation infrastructure handling 8-figure daily settlement across three chains.
- Settled monthly
- $420M
- Chains live
- 3
- Custody cost
- −41%
- Material errors caught
- 7
- Client
- Cobalt Money
- Vertical
- Crypto · payments
- Region
- Singapore + EU
- Year
- 2025
- Duration
- 10 months
- Team
- 4 engineers · 1 security engineer
- Role
- Custody · settlement · reconciliation
Overview
What we walked into.
Cobalt issues a fiat-collateralised stable-coin used for cross-border B2B settlement. They needed to hand off custody operations from a third-party provider to in-house infrastructure three chains, multi-signature wallet management, real-time reconciliation against off-chain bank balances.
Replace a vendor's custody system with an in-house implementation that met the same security bar (HSM-backed signing, threshold approvals, withdrawal allowlists) while clearing settlement faster and at lower cost. Eight-figure daily volume meant a single bug could be material.
Approach
What we built.
02
Real-time reconciliation
Every chain event maps to an off-chain ledger event within seconds. Discrepancies trigger an automatic freeze and page the on-call engineer with the exact divergent transaction. We caught two errors during the first month that the previous vendor's reconciliation hadn't surfaced for weeks.
03
Withdrawal policy engine
Configurable rules daily limits, allowlists, velocity checks, jurisdiction routing. All policy decisions logged with the rule that fired, so compliance can audit the chain of evaluation behind any settlement event.
Outcome
What shipped.
Cobalt now settles $420M/month across Ethereum, Base, and Solana on the platform we built. Per-transaction custody cost is 41% lower than the previous vendor's, and the reconciliation engine has caught seven discrepancies that would have been six-figure-or-larger losses.
We trust the system enough that I sleep through the night. That sounds boring for crypto custody, it's the highest possible compliment.
Stack
- Rust
- TypeScript
- PostgreSQL
- AWS Nitro Enclaves
- YubiHSM
- Foundry
Ready when you are.
Thirty minutes. We'll listen, and we'll tell you plainly whether this is a fit. If it isn't, we'll point you at someone it is.
No discovery deck. No sales call. One conversation.