FinTech & Marketplaces
Payments, wallets, lending and two-sided marketplaces, where the ledger has to survive a reversal that arrives days late.
The context
The money does not move inside the product. It moves on rails the software does not control: a card network, a bank and a settlement file that arrives the next day. What has to be engineered is a record that reconciles against all three, and SAMA decides much of what that record contains.
What makes it hard
Reconciliation after the fact
The truth about a payment arrives late, in a settlement file, sometimes days after the customer saw a receipt. An append-only ledger survives that — a balance updated in place does not.
Retries that charge twice
A card authorization that times out may still have succeeded at the network. Without an idempotency key carried on the retry, the second attempt becomes a second charge and then a dispute.
PCI scope as an architecture decision
Where card data is allowed to land decides which services fall in scope. Scope drawn late is paid for in a re-architecture, not a policy document.
One record, three postings
A marketplace collects once and pays out many times. Commission, the seller invoice and the payout come out of one record, and a refund after payout has to unwind all three.
How we help
- The ledger is designed before the screens, as append-only entries with the balance derived from them.
- Idempotency keys, retries and out-of-order webhooks are specified in the first architecture review rather than discovered in a production incident.
- The boundary that puts card data inside the payment provider scope is drawn in the architecture, not found in an audit.
- Data residency, audit retention and what a regulator can ask to see are architecture inputs, not a compliance pass at the end.
- Reconciliation runs as a monitored job, not a spreadsheet at month end.
- SAMA rules on payments, wallets and consumer finance
- PCI DSS scope and where card data is allowed to land
- mada, SADAD and sarie as the domestic rails
- Nafath and Wathq in onboarding and seller verification
- AML screening and transaction monitoring on every counterparty
- ZATCA e-invoicing, PDPL and in-Kingdom data residency
Related services
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