INDUSTRIES
Payments, banking, and trading systems where a rounding error becomes a regulatory event — built by a team that has moved half a billion dollars through one.
We built the payment infrastructure behind more than $500 million in transactions, running at 99.99% reliability, plus a banking app serving over one million users at 99.9% uptime. Money systems teach you things no tutorial covers — what happens when a webhook arrives twice, when a settlement file is late, when a ledger and a bank statement disagree by four cents.
Four kinds of build, from a first payment flow to a platform under regulatory scrutiny.
Payment gateways and processing infrastructure that stay correct under retry and failure. Tokenized card handling, multi-rail support, and reconciliation built in from the first integration rather than added when the first discrepancy appears.
Banking and wallet applications with biometric authentication, real-time balances, and offline states that behave. Built as mobile apps for both stores, or as web platforms, depending on how your customers actually bank.
Trading and investment platforms where latency and order accuracy decide everything. Order management, position tracking, and market data handling designed for the volumes you expect at peak rather than the ones you see on day one.
Lending, underwriting, and risk systems that combine automated decisioning with an audit trail. Every decision traceable to the rule and the data that produced it, because that's what a regulator asks for.
Fintech software development is the building of applications that move, hold, or make decisions about money — payment processing, banking platforms, trading systems, and lending infrastructure. The constraint that separates it from general software development is correctness under failure. In most systems a failed request is retried and forgotten. In a payment system, a retry without an idempotency key charges someone twice, and the fix is a refund, an apology, and a line in a report somebody reads.
A double-charge isn't a bug ticket — it's a chargeback, a support call, and potentially a regulatory question. We design for exactly-once behavior using idempotency keys, daily reconciliation against the processor, and alerts that fire on a discrepancy rather than on an outage. That's back-end engineering more than anything else.
PCI DSS shapes the architecture before the first screen is designed. Card data either stays out of your systems entirely through tokenization and hosted fields, or your compliance scope expands to include every server that touches it — along with the logging, access control, and quarterly scanning that come with it.
We design for the smallest scope that meets the requirement, then document exactly which systems fall inside it. That document is what your assessor asks for first.
The same approach applies to SOC 2 and GDPR. We build to what each requires and tell you upfront how it shapes the timeline. We're not an auditor and don't issue certifications.
Integration count moves a fintech project's timeline more than feature count does. A wallet with one payment method and a multi-rail platform with reconciliation and reporting are different builds entirely, even if the feature list looks similar.
Common integrations: card networks, ACH and wire rails, open banking APIs, KYC and AML providers, core banking platforms, and the ledger systems your finance team already reconciles against.
Which is why discovery is fixed-price and happens before any estimate — the integration audit is where the real number comes from.
Go, Node.js, and Java behind PostgreSQL, with Redis for caching and Kubernetes for orchestration. React Native where a mobile app is part of the build.
Boring, well-understood technology by design. A payment system is not where you try something new, and the stack that processed your $500 million should be one your own team can hire for.
Discovery is fixed-price and produces a costed estimate before development starts. Three things move the number more than anything else:
Compliance scope. PCI DSS, SOC 2, and regulatory reporting each add architecture, testing, and documentation that don't appear on a feature list.
Integration count. Each rail, provider, or legacy system adds real time. A documented modern API might add a week; an undocumented core banking system can add a month by itself.
Reconciliation requirements. Matching your ledger against multiple processors daily is a system in its own right.
We don't quote from a price list. You get a costed timeline in writing after discovery.
Money systems still processing transactions today.
A HIPAA-ready platform that pulled telemedicine, scheduling, and billing into one system for a multi-clinic network.
A high-availability payment gateway that has processed over $500M in transactions at 99.99% reliability.
Our Fintech Software Development Process
The same delivery process behind 800+ projects, applied to systems where a mistake has a price attached.
01
We map the money flows, the failure modes, and which regulations apply to which parts.
02
Ledger design, idempotency strategy, and compliance scope settled before code.
03
Flows prototyped against real edge cases — declines, partial refunds, disputes, chargebacks.
04
Two-week sprints with reconciliation running from the first integration.
What clients in fintech ask us most often.
Still have questions?
Talk to an engineerWe design so card data never touches your servers where possible, using tokenization and hosted fields. That keeps your PCI scope small. Where data must be handled, we document exactly which systems fall in scope and build the controls the standard requires.
Every write carries an idempotency key, so a repeated request returns the original result instead of creating a second charge. Reconciliation jobs then compare your ledger against the processor daily and flag anything that doesn't match.
Yes. Plaid, Stripe, Adyen, Marqeta, and the major KYC and AML providers are standard work. We also integrate with core banking platforms and legacy systems that predate any of them.
Discovery is fixed-price and produces a costed estimate. Compliance scope and integration count move the number more than feature count does. A single-rail wallet and a multi-rail platform with daily reconciliation are different builds entirely.
A focused first release reaches production in three to four months. Larger platforms ship in phases, so parts of the system are live and processing while later modules are still in development.
You do. Source code, infrastructure definitions, and design files live in your repositories and cloud accounts from the first sprint, which also matters for the vendor assessments your partners will run.
Tell us what the money flow looks like and we'll map it into an architecture, compliance scope, and estimate — at no cost.