FinTech
In fintech three things pull against each other: the ledger has to be provably correct, the regulator has to be satisfied, and the customer has to get through onboarding. Most of the engineering is in how you resolve that tension — deliberately, and with the evidence to show your working.
Where fintech engineering actually gets hard.
Not in the product surface. In correctness under failure, in the evidence an auditor will ask for two years later, and in the friction compliance adds to a customer’s first five minutes.
Money needs a real ledger
Balances derived from mutable rows drift, and the drift is discovered at month-end. Double-entry with immutable postings is the version that reconciles — and retrofitting it after launch means rebuilding the core while it holds customer funds.
Compliance is evidence, not intent
KYC, transaction monitoring and safeguarding have to be demonstrable: decisions logged, rule versions retained, and an auditor able to reconstruct why a specific customer was approved eighteen months ago.
Onboarding friction costs customers
Every additional check reduces completion. The real work is separating the friction that is legally required from the friction inherited from someone else’s template.
Failure has to be safe
Payments cross systems you do not control. Retries, timeouts and partial failures must never double-spend, which makes idempotency and reconciliation design constraints rather than implementation details.
Build the ledger and the audit trail first.
Model the ledger
Double-entry with immutable postings, so every balance is derivable and every movement has an explanation.
Design the controls
Screening and monitoring as versioned rules with logged decisions, built for the evidence an audit will actually request.
Integrate the rails
Payment providers and open-banking APIs with idempotency keys, reconciliation and a tested position on partial failure.
Instrument the breaks
Reconciliation mismatches and control failures raised as alerts, rather than discovered during month-end close.
A ledger that reconciles and an audit you can answer.
What changes for the people doing the work, not just for the systems behind them.
- Double-entry ledger where every balance derives from immutable postings
- KYC and monitoring decisions logged against the rule version that made them
- Idempotent payment flows that survive retries and partial failures
- Automated reconciliation against provider and bank statements
- Onboarding measured step by step, so friction is a choice rather than an accident
- Segregated environments and access controls an auditor can inspect
What we usually bring to this sector.
The things this sector asks first.
You need your own. We build and operate technology — we do not hold permissions, act as your agent, or carry regulatory responsibility for your product. Where you work through a sponsor bank or an EMI partner we build to their requirements, but the relationship and the obligation remain yours, and any supplier telling you otherwise is worth questioning.
Ledger-as-a-service has matured and is often the right call early on. Build your own when your product needs postings a generic ledger cannot express, or when the provider becomes a concentration risk you are not willing to carry. What we will not do is derive balances from a mutable table and call it a ledger — that is the decision people regret.
Through specialist providers for identity verification and screening, integrated so every decision, the rule version behind it and the supporting evidence are retained. The engineering value is in the audit trail and in tuning false positives against real cost — not in rebuilding sanctions screening yourself.
Reduce the scope before you engineer for it. Tokenised, provider-hosted card capture keeps card data out of your systems entirely and turns a heavy compliance burden into a much lighter one. Where full scope is genuinely unavoidable we build to it, but scope reduction is almost always the cheaper decision.
With provider sandboxes, deterministic test doubles for the failure modes sandboxes will not reproduce, and reconciliation checks that run in every environment. Timeouts, duplicate callbacks and out-of-order settlement are all rehearsed deliberately, because production is a bad place to find out how they behave.
Have an idea? Let’s forge it.
Tell us where you want to go. We’ll help you get there with the right technology, delivered by a team that ships.