Fintech software development
Fintech software built around the regulated perimeter
The expensive mistakes in fintech are not bugs. They are card numbers stored where they never needed to be, or a licensed activity built in-house by accident. We draw the perimeter first: what your partners hold, what you hold, and what the software must never touch.
- Peer-reviewed releases
- NDA before your first call
Draw the perimeter before the architecture
Every fintech product sits on regulated activity: moving money, holding it, lending it, checking who a customer is. Most companies do not hold every licence that activity needs, and should not try. They work with a bank, a payment processor, an identity provider or a lending partner who does.
The software’s job is to sit around that perimeter cleanly. When it crosses it, by storing card data, making a credit decision it should not, or keeping customer money in the wrong account, the fix is rarely a code change. It is an audit, a remediation plan and sometimes a regulator.
So fintech work starts with three lines drawn on paper.
- 01
What partners hold
Card data, customer funds and licensed decisions stay with the licensed partner.
- 02
What you hold
The customer relationship, the product logic and the data you are entitled to keep.
- 03
What must never cross
Raw card numbers, credentials and anything that widens your compliance scope.
What we build
Fintech software we develop
Six kinds of system, each built on the partners and rails the product depends on.
- 01
Payments and wallets
Checkout, payouts and wallet features built on a processor’s tokenised APIs, so card data never reaches your servers.
- 02
Lending platforms
Loan origination and servicing workflows: applications, document collection, decisions from your credit partner, repayments and collections.
- 03
Wealth and investment tools
Portfolio views, onboarding and reporting built on a custodian’s or broker’s APIs.
- 04
Onboarding and KYC flows
Identity verification and screening through a specialist provider, with the audit trail your compliance team will be asked for.
- 05
Back-office and reconciliation
Ledgers, reconciliation against bank and processor reports, and the exception queues that finance teams work every day.
- 06
Reporting and compliance data
Regulatory and management reporting built from the ledger, not from spreadsheets assembled at month end.
Integration
The systems a fintech build has to talk to
Most of a fintech product’s behaviour is borrowed from partners. These are the usual counterparts and where the trouble starts.
| Counterpart | Usual interface | What goes wrong |
|---|---|---|
| Payment processor | REST APIs, hosted fields, webhooks | Webhooks that arrive late, twice or out of order |
| Banking partner | Banking APIs, file transfers, ISO 20022 messages | Settlement files that do not match what the API reported |
| Identity and KYC provider | REST APIs, SDKs | Manual review queues nobody sized |
| Credit bureau or lending partner | Partner APIs | Decisions that must be explained to the customer, not just stored |
| Accounting and ERP | APIs, scheduled exports | Two ledgers that drift apart a cent at a time |
The pattern behind all five: treat every partner message as something that can arrive late, twice or not at all, and reconcile against the partner’s own reports. It is the same discipline behind our custom software development work: the integrations are scoped before the price.
Before you build
What to settle before a fintech build starts
Seven questions to answer in writing with any fintech software vendor, including us. The PCI Security Standards Council publishes what counts as cardholder data and why reducing scope matters.
PCI Security Standards Council- 01Which licensed partner performs each regulated activity: holding funds, processing cards, lending, identity checks.
- 02Whether card data will ever reach your servers, and if not, how the design guarantees it.
- 03Which system is the ledger of record, and how it is reconciled against the bank and processor every day.
- 04What happens when a partner’s webhook arrives twice, late or never.
- 05What your compliance team will need to evidence, and where the audit trail for each decision lives.
- 06Which data you may keep, for how long, and where it is hosted.
- 07Who owns the partner accounts, the keys and the code when the engagement ends.
Answer these first and most of the architecture follows from them. Leave them open and the architecture decides them for you, usually in the most expensive direction.
Compliance, explained
What each rule changes in the build
Compliance in fintech belongs to the regulated entity. The software’s job is to keep scope small and evidence easy to produce.
- 01
PCI DSS
Under PCI DSS, any system that stores, processes or transmits card data is in scope. Tokenised checkout and hosted payment fields keep raw card numbers off your servers, which shrinks what has to be assessed.
- 02
KYC and AML
The obligations, built on the FATF Recommendations in most countries, sit with the regulated entity. The software provides the verification flow through a specialist provider, the screening records and the audit trail an examiner will ask for.
- 03
SOC 2 reports
Banks and enterprise buyers often ask their vendors for a SOC 2 report. It describes the controls around your systems, so build logging, access control and change management in from the start.
- 04
DORA (EU)
Since January 2025, DORA requires EU financial entities to manage ICT risk, including the third parties they rely on. If your customers are EU financial firms, expect questions about resilience, incident reporting and exit plans.
Proof
Rated by the clients who have worked with us
Fintech is one of the sectors we have shipped systems into. We name clients only with their written permission, so our reviews live on Google and Clutch, where we cannot edit them.
When to buy a platform instead
Three cases where we would tell you not to build:
- 01
A banking-as-a-service platform covers it
If a licensed platform already offers the accounts, cards or payments you need through its API, build the customer experience on top, not the core.
- 02
The product is a standard ledger
Accounting and standard lending products are mature. Configure one unless your product logic genuinely differs.
- 03
You cannot staff the compliance side
Custom software means your team evidences its controls. Without someone to own that, a regulated platform carries the load better.
Custom work pays where the product logic, the customer experience or the reconciliation between partners is what makes your business different.
How we work
From the perimeter to a product in use
The same five stages we use for every engagement, with notes where fintech changes a stage.
Discovery
We map your workflows, systems, and constraints with the people who use them every day, before anything is scoped.
For fintech: the perimeter drawn, each partner named, and the data your compliance team must evidence listed.
Scope and plan
You get a scope, a timeline, and a price that hold. Architecture decisions are made and documented before code starts.
Build in stages
Senior engineers deliver in planned stages, with working software demonstrated at every step, not a reveal at the end.
For fintech: partner sandboxes first, with duplicate and late messages tested deliberately.
Launch
Data migration, training, and a production cutover planned around your operations and your calendar, not ours.
Run and improve
The team that built your system stays on it: monitoring, support, and the next improvements on one roadmap.
For fintech: daily reconciliation against partner reports, with exceptions queued rather than corrected silently.
FAQ
Questions buyers ask about fintech software development
What does a fintech software development company do?
It builds the software financial products run on: payments, lending, wealth, onboarding and back-office systems, integrated with the banks, processors and providers that hold the licences.
How much does fintech software development cost?
It depends on the number of partners to integrate, the reconciliation involved and the compliance evidence required. We do not publish prices; our guide to what decides custom software cost explains why quotes for the same product differ.
Do we need a banking licence to build a fintech product?
Often not. Many products work with a licensed partner that holds the funds or performs the regulated activity, and build the customer experience around it. Which licences you need is a question for a regulatory lawyer, and it should be answered before the architecture.
How do you handle card data and PCI DSS?
By keeping it away from your systems wherever possible. Tokenised checkout and hosted payment fields from the processor mean raw card numbers never reach your servers, which keeps most of your software out of PCI scope.
Can you integrate with our bank or payment processor?
Yes, through their APIs, files or both. We build every integration expecting messages to arrive late, twice or not at all, and reconcile against the partner’s own reports.
How long does a fintech build take?
A focused product on one partner can take a few months. Each additional partner, market or regulated feature adds time, mostly in integration testing and approvals. We give a timeline after discovery.
Can you modernise a legacy banking or lending system?
Yes, in stages, with both systems running and their outputs compared until they agree. Our application modernization service explains how.
Who owns the code and the partner accounts?
You should. The code, the cloud accounts, the partner accounts and the keys should be in your name, written into the contract before the work starts.
Start with the perimeter,
then the product
Tell us what the product does and which partners hold the licences. We will draw the perimeter and the integrations before we estimate.
