Fintech Software Development Services
A fintech product is a set of money movements that must always add up. We build payment, lending, wallet and investing software around a correct ledger, tested integrations and auditable security, then put a product people enjoy using on top.
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What Fintech Software Development Covers
Ledger & transaction engines
Double-entry ledgers, balances, holds and reconciliation that stay correct under retries and partial failures.
Payments & payouts
Card, bank transfer and local payment methods through processors, with webhooks, refunds and disputes handled.
Lending & credit workflows
Applications, scoring integrations, offers, repayment schedules and collections.
Open banking & data
Account aggregation, transaction categorisation and affordability checks through regulated providers.
Built for Specific Buyers, Not Everyone
Funded fintech startups
Need a senior team to build the regulated core of the product correctly the first time.
Financial institutions
Adding a digital product line without waiting for an internal platform roadmap.
Companies embedding finance
Adding payments, lending or wallets to an existing platform or marketplace.
If you only need a simple checkout on a website, a hosted payment page from your processor is cheaper than custom fintech engineering.
From Kickoff to Launch
Money-flow discovery
Every flow of funds, partner and failure case mapped before estimates.
→ Flow map + scopeArchitecture & security design
Ledger model, idempotency, secrets, encryption and access control agreed.
→ Architecture documentSandbox build
Features built against partner sandboxes with automated reconciliation tests.
→ Tested release candidateGo-live & operations
Penetration test support, monitoring, alerting and on-call handover.
→ Production platformTechnologies We Use
Compliance and Standards We Build To
PCI DSS
Card data handled by PCI-compliant processors and tokenised, so your platform stays out of scope wherever possible.
PSD2 / open banking
Strong customer authentication and account access through regulated aggregators and bank APIs.
KYC / AML
Identity verification, sanctions screening and transaction monitoring through specialist providers, with audit trails.
SOC 2 / GDPR-ready engineering
Encryption, access control, logging and data retention designed in from the first sprint.
Related Work
ETF Europe
A platform that simplifies buying ETFs, with filters that help investors find funds that fit their needs.
Finance Brokers
A Romanian digital mortgage platform that helps people compare banks and arrange a mortgage on better terms.
iGIVIT
A crowdfunding platform that lets supporters donate through the blockchain as well as by card.
Common Questions About Fintech Software Development
What does Northell Design include in fintech software development?
Architecture, ledger and transaction design, payment and banking integrations, KYC and onboarding, customer apps, back office, security engineering, testing against partner sandboxes, and support after launch. Product design is included when you need it.
How does Northell Design keep financial data secure?
Card data stays with PCI-compliant processors and is tokenised. Everything else is encrypted in transit and at rest, secrets are managed outside the code, access is role-based and logged, and we support your penetration tests and security reviews before go-live.
Can Northell Design take over an existing fintech codebase?
Yes. We start with a code, ledger and integration review to find where balances or reconciliation can drift and where security is weak, fix the risky parts first, then continue feature work.
Which payment and banking providers can you integrate?
Processors such as Stripe and Adyen, open banking aggregators, card issuing and banking-as-a-service platforms, KYC providers and accounting systems. We confirm each provider's API and licensing constraints during discovery.
How do you prevent balance and reconciliation errors?
With a double-entry ledger, idempotent APIs, webhook replay handling and automated reconciliation against partner reports, so every discrepancy is detected and explained rather than silently absorbed.
Do you help with regulatory approval?
We don't provide legal advice or licences, but we design the system so your compliance team can evidence controls: audit logs, access reviews, data retention and change history.
How is a fintech development project priced?
After a scoping call we propose either a fixed-scope first release or a dedicated team, depending on how settled the requirements are. We don't publish one price because partner and regulatory scope change it significantly.