Case study · 2025 · Fintech · Payment Platforms
Cross-Border Payout Rails for a Global Marketplace
A services marketplace was paying sellers in 30+ countries through correspondent banking: three to five days in transit, opaque fees at both ends, and a support queue full of "where is my money." We built parallel payout rails on stablecoins — smart-contract escrow releasing on delivery confirmation, compliance screening in the flow, automatic conversion to local currency through licensed off-ramp partners — so a seller in one of the marketplace's largest corridors gets paid the same afternoon.
Screens are illustrative recreations — client interfaces stay confidential.
The challenge
Cross-border payouts were the marketplace's loudest complaint and a real competitive leak — sellers compared arrival times with rival platforms, and the 3–5 day window plus double-ended fees was losing them.
The finance team's constraint was harder than speed: every payout, on any rail, had to reconcile automatically against marketplace ledger entries, and screening obligations applied identically regardless of settlement technology.
What we built
Escrow as a contract
Buyer funds settle into audited escrow contracts on a low-fee network; release conditions mirror the marketplace's delivery-confirmation and dispute states, with a timelocked admin path for the edge cases contracts can't judge.
Compliance in the flow, not after
Payouts pass sanctions and risk screening through the marketplace's existing provider before funds move; flagged transactions hold in escrow under the same review workflow the fiat rails use.
Local currency by default
Licensed off-ramp partners convert USDC to local currency automatically per seller preference — sellers see their own currency in their own account, with the stablecoin leg as invisible plumbing.
Reconciliation as a first-class system
A Go settlement service matches on-chain events to ledger entries continuously, with exception queues for anything unmatched — month-end close on the new rails is a report, not a project.
The results
- <30 min
- Median payout time
- −70%
- All-in payout cost
- 100%
- Automated reconciliation
from 3–5 days on correspondent rails
three largest corridors, fees plus FX spread
on-chain events matched to ledger entries
All-in cost including network fees, partner fees, and FX spread; corridors anonymized.
View the data as a table
| Correspondent rails | Stablecoin rails | |
|---|---|---|
| Corridor A | $32 | $9 |
| Corridor B | $24 | $7 |
| Corridor C | $41 | $12 |
- Median payout time on migrated corridors fell from 3–5 days to under 30 minutes, including conversion to local currency.
- All-in payout cost dropped about 70% on the three largest corridors, most of it returned to sellers' pockets.
- Reconciliation runs at 100% automation, and payout-related support tickets fell by more than half within two months of corridor migration.
Client identities stay confidential; figures are rounded from end-of-engagement delivery reporting.
Stack & expertise
- Go
- Solidity
- PostgreSQL
- USDC on an EVM L2
- licensed off-ramp partners
Security Hardening for a Payments Platform
An authorized penetration test and remediation cycle — 32 findings fixed and retested, 4 of them critical, with the API attack surface cut by 60%.
Verified Ticketing & Collectibles for a Live-Events Group
On-chain ticket issuance with rotating gate codes and post-show collectibles — 38,000 tickets issued, duplicate-entry incidents effectively eliminated.
QA Engineering Program for a Digital Lending Platform
A risk-based QA system — automation in CI, exploratory charters, load suites — that cut regression from 3 days to 42 minutes and escaped defects by 77%.