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BigTree108

Fintech software development services

Fintech software development for payment companies, digital wallets, card issuers, lenders, trading and wealth platforms and finance tools for businesses: payment gateway and PSP integrations, ledgers and reconciliation, card issuing, open banking, KYC, AML and fraud detection, built to PCI DSS, PSD2 and DORA requirements, with dedicated fintech developers for your team or a product delivered end to end.

What we build for fintech

  • Payment processing

    Checkout, payouts and subscriptions on Stripe, Adyen, Checkout.com, Braintree and local acquirers, with idempotency keys, retries and webhook handling, so a network timeout never charges a customer twice.

  • Ledgers and reconciliation

    Double-entry ledgers as the system of record for money, every balance derived from entries, and daily reconciliation against bank and provider statements with breaks queued for a person.

  • Digital wallets and card issuing

    Stored-value wallets, virtual and physical cards through issuing platforms such as Marqeta, Stripe Issuing and Adyen Issuing, spending controls, and Apple Pay and Google Pay provisioning.

  • Open banking

    Account information and payment initiation through PSD2 APIs and aggregators such as Plaid, TrueLayer, Tink and GoCardless, with consent flows and token renewal built in.

  • KYC, AML and fraud

    Identity checks with Onfido, Sumsub or Veriff, sanctions and PEP screening, transaction monitoring rules and machine-learning fraud scores, with case management for the analysts who review alerts.

  • Trading and wealth platforms

    Brokerage and investment apps, order management, market data feeds, FIX connections to brokers and exchanges, and portfolio and performance reporting.

  • Finance tools for businesses

    Invoicing, expense management, accounts payable automation and treasury dashboards, connected to Xero, QuickBooks, NetSuite and Dynamics 365.

  • Digital assets

    Custody wallet integrations, exchange and on-ramp APIs, and the travel rule checks and MiCA reporting a regulated crypto-asset service needs, built with our blockchain developers.

Hire fintech developers

  • Dedicated fintech developers

    Fintech developers who join your team full time, work in your tools and process, and report to your lead. You interview them; we carry the Ukrainian contract, payroll, invoicing and leave.

  • Fintech software development projects

    A defined piece of fintech software development with a scope, a fixed plan and a named lead on our side who owns the result and reports progress in your channels.

  • Ongoing fintech software development

    Fintech software development as a continuing service: the same people every month, a backlog you prioritise, and hours you can see in our portal and on the invoice.

The dedicated team page explains how specialists join your team, and the outsourcing page covers project delivery, take-overs and how we charge.

Who works on your fintech software development

  • Backend engineers

    .NET, Java, Go or Python services for payments and ledgers

  • Front-end and mobile engineers

    Web and mobile apps with secure payment flows

  • Business analysts

    Payment flows, fee rules and regulatory requirements

  • QA engineers

    Payment scenarios, provider sandboxes and reconciliation checks

  • DevOps and security engineers

    PCI DSS scope, key management and audit logs

Built for money that has to add up

Every amount is an integer in the smallest currency unit, every money movement is an entry in a ledger, and every call to a provider carries an idempotency key, so retries, duplicates and partial failures leave balances right. Reconciliation runs from the first release, not after the first missing payment.

Card data stays out of your systems through tokenisation and hosted payment fields, which keeps PCI DSS scope small. Production access is limited, logged and reviewed, and the controls, audit trails and recovery tests that DORA, PSD2 and your regulator ask for are part of the design rather than a project before the audit.

Other industries we build for

Industries overview

Questions about fintech software development

Do you build to PCI DSS?

Yes. The design keeps card data out of your systems through tokenisation and the provider’s hosted fields, and what remains in scope gets the controls PCI DSS v4 asks for. The assessment itself is made by a Qualified Security Assessor or through your self-assessment questionnaire; our part is the controls and the evidence they test.

Can you integrate our bank or payment provider?

Yes. Each integration starts in the provider’s sandbox with timeouts, declines, duplicate webhooks and refunds written as tests, and goes live behind a switch you control, so it can be turned off without a release.

How quickly can fintech developers start?

When the right fintech developer is available, the start is gated only by your interview and the NDA and IP assignment. Otherwise we run a search, which typically produces candidate profiles within two to three weeks, and nobody starts until you have said yes.

How do we hire fintech developers through BigTree108?

Tell us the work, the seniority and the hours you need. We propose one or two people with their profiles, you interview them the way you would interview your own hire, and you sign one agreement with BIG TREE 108 LLC and receive one invoice a month.

Who owns the work they produce?

You do. Every specialist has a signed contract with BigTree108 that assigns all work product to the company, and our agreement with you assigns it onward. Code, designs and documents are delivered into your own repositories and tools, not kept where only we can change them.

Building a fintech product?

Tell us the product, the providers you use and the regulations you work under. You get an answer within one business day: candidate profiles or a plan for the work.

Email hello@bigtree108.com How we respond