Fintech consulting for software that moves money
My fintech consulting is engineering work: making the software that holds, moves and reports money correct, auditable and calm under load. That means ledgers that balance, payments that never double-charge, reconciliation that catches drift before your finance team does, and architecture your compliance team can sign off on.
I’m not a regulatory or licensing advisor – you need specialist lawyers and compliance people for that. I’m the engineer who builds the system they can trust, and I start with a two-week sprint.
Correctness first: the engineering rules I hold fintech code to
- Integers in minor units, never floats. Store cents (or the currency’s smallest unit) with the currency code next to it. Round once, at a defined point, with a defined rule.
- Double-entry ledger. Every movement is at least two entries that sum to zero. Balances are derived from entries, not stored as a number that gets updated in place.
- Append-only history. Corrections are new reversing entries, not edits. If a row that represents money can be UPDATEd, someone eventually will.
- Idempotency everywhere money moves. Every request to charge, refund or pay out carries an idempotency key, stored with a unique constraint, so a retry can never become a second payment.
- Webhooks are hints, not truth. They arrive late, out of order and more than once. Verify the signature, record the event, then fetch the current state from the provider before acting. My Stripe webhook guide covers this in detail.
- Explicit state machines for payments, payouts and disputes, with every transition logged and illegal transitions rejected in code.
Audit trails and reconciliation
In fintech, “what happened and who did it” must have an answer for every money-related change. That means an audit log written in the same database transaction as the change it records, including actor, timestamp, before and after values, and the reason or ticket. Admin actions that move money need the same trail as customer actions, and ideally a second person’s approval.
Reconciliation is the other half. Your ledger, your payment provider’s settlement reports and your bank statements will drift: fees you didn’t model, FX differences, a refund issued in the provider’s dashboard. A daily automated reconciliation job that matches the three and raises breaks for a person to resolve is the control most often missing. The payment reconciliation guide walks through how to build one.
Compliance-aware architecture
I don’t interpret regulations for you, but I do design systems that make compliance work cheaper:
- Shrink PCI scope. Use your provider’s hosted fields or tokenization so card numbers never touch your servers. Then confirm the resulting scope with your assessor.
- Separate sensitive data. Identity documents, bank details and KYC results in their own store with tighter access and their own retention rules.
- Least privilege and separation of duties in production access, with access logged and reviewed.
- Data retention that’s enforced in code, not just written in a policy document.
- Evidence on demand. Change history, access logs and incident records your auditors can be given without a scramble.
Where this experience comes from
I built the payment platform at Yola as an early engineer, and architected the backend and payment integrations for BLU Loyalty, an enterprise loyalty platform with 9M users in the UAE. The software studio I co-founded delivered fintech work among 200+ projects, and I’ve worked across engineering, architecture and cloud infrastructure at Pepkor NexTech.
I also wrote the Payments Playbook, a book on building payment systems that survive real customers. It was seven years in the writing.
How a fintech engagement starts
Typically with a question like “our balances don’t match Stripe” or “we’re about to launch payouts and nobody has done this before”. The two-week sprint covers a review of how money flows through your system end to end, the highest-risk gap fixed in code, and a written list of what else I’d change. From there I can stay on as a part-time technical lead or fractional CTO, or hand a plan to your team.
If you’re a non-fintech company adding payments to your product, payment integration is the more relevant page.
Questions
What does a fintech software consultant do?
A fintech software consultant designs and builds the technical side of financial products: ledgers, payment flows, reconciliation, audit trails, security controls and integrations with providers and banks. It is distinct from regulatory or licensing consulting, which needs legal and compliance specialists.
Do you help with fintech licensing or regulatory compliance?
No. I don’t give legal or regulatory advice. I work alongside your compliance team and advisors, turning their requirements into architecture and code – audit logs, data separation, access controls, retention – and producing the technical evidence they need.
When does a fintech need a fractional CTO?
Often earlier than a typical SaaS, because mistakes in money handling are expensive and hard to reverse. Common moments are before launching payouts or stored balances, before a partner bank or acquirer’s technical review, and when reconciliation breaks start appearing.
Should we build our own ledger?
If money is your product, you need a ledger you understand and control, whether built in-house on PostgreSQL or using a dedicated ledger service. If payments are incidental, rely on your provider’s records plus a simple internal ledger for reconciliation. Never rely on a mutable balance column.
Building software that moves money?
Tell me how money flows through your product and where it worries you. In two weeks you’ll have the biggest gap fixed and the rest written down.
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