Payments, bank account linking, wallets, lending MVPs and identity checks for fintech startups and scale ups. We build the product and connect it to the specialist providers that hold the card numbers, the identity documents and the money, so your own systems hold as little of each as the product allows.
Custom fintech software development is the design, build and upkeep of a product that moves, holds, lends or verifies money for its users: a payments platform, a wallet, a lending app or an onboarding flow. Specialist providers such as Stripe, Plaid and Persona do most of the regulated work. The custom part is the product around them, and the records that tie each user to what those providers hold.
This page is for founders and product teams launching a fintech product. If you need software for a finance team instead, such as reporting, accounting tools or a client portal for a wealth firm, our financial software development page covers that work.
from a 30-minute call to a written scope and quote
of discovery, priced on its own, before a fixed build price
for a typical MVP build once discovery ends
Five products cover most of what fintech founders bring to a first call. Each one rests on a provider that carries the regulated part, and each has a part that only your own team, or ours, can build.
Checkout, saved payment methods, refunds and disputes, and for a marketplace, the split between your platform and the sellers it pays. On Stripe Connect, the platform decides who collects fees, who carries losses and who gathers each seller's identity details. Those choices are costly to reverse once sellers are live, so we settle them in discovery.
Plaid Link connects a user's bank account inside your app. Plaid then returns what the product needs: account and routing numbers for ACH transfers through Auth, live balances through Balance, ownership checks through Identity, and history through Transactions. We build the screens around Link, keep the access tokens on the server, and handle the day a connection breaks and the user must sign in to the bank again.
A wallet that holds customer money needs a licensed home for that money: a partner bank, or a provider licensed to transmit money. We build the wallet app, the top up and transfer flows, and the records that show each user's balance, on top of that partner. Those records must agree with the partner's every day, for the reason the Synapse section below gives.
The application, document upload, a call to your credit rules or a vendor's, the offer, the repayment schedule and the servicing screens. The first version is scoped to one loan product and one decision path, so it can lend to real applicants before a second product is added. The lending section covers the two outputs regulators read first.
Persona offers government ID, selfie, document and database checks that can be combined in one inquiry. Alloy works a layer up, running KYC, KYB, AML and watchlist screening across many data vendors and routing each case. We place the checks in the onboarding flow, build the review queue for cases a vendor cannot decide, and keep a record of every decision and its reasons.
We design a fintech product around one rule. Card numbers, identity documents and customer money should each sit with a specialist provider set up to hold them, and your systems should keep references instead. Each of the three you hold yourself brings an audit, a licence or a breach duty that the provider would otherwise carry. The table shows where each belongs and what your app keeps.
| What is sensitive | Where it should sit | What your app keeps | If you hold it yourself |
|---|---|---|---|
| Card numbers | The payment processor, through its hosted page or embedded form | A token, the card brand, the last four digits and the expiry date, which Stripe says sit outside PCI scope | Far more of PCI DSS, which Stripe says can mean more than 300 security controls |
| Identity documents and selfies | The identity vendor, such as Persona or Alloy | The inquiry ID, the result and the reasons for the decision | Storage, access and deletion duties for the most sensitive files in the product, and more data to report if it is breached |
| Customer money | A partner bank or a licensed money transmitter | Each user's balance and history, checked daily against the partner's own report | Money transmitter licences, which in the US are granted state by state |
The rule has a cost, and we say so in discovery: every provider you rely on is a contract, a monthly bill and a point of failure. For an MVP that trade is almost always worth making, because the alternative is an audit or a licence application before the first user signs up.
Stripe is assessed every year as a PCI Level 1 service provider, but that covers Stripe, not you. By Stripe's own security guide, a business taking card payments must still attest to its own compliance every year. How much work that attestation is depends on one design choice: where the customer types the card details.
| How the card is taken | What the customer sees | Usual questionnaire | What it asks of you |
|---|---|---|---|
| Redirect to Stripe Checkout | A payment page on Stripe's domain | SAQ A | The fewest controls; the script criterion does not apply to a redirect |
| Embedded form (Elements) | Card fields inside your page, served in a frame from Stripe's domain | SAQ A | Confirming your page is not open to script attacks, by your own controls or the provider's confirmation |
| Official mobile SDK screens | Stripe's own card screens inside your app | SAQ A | Using only the SDK's UI components; your own card code can end eligibility |
| Your own card form, sent to the API | Fields you built, on servers you run | SAQ D | The full standard, because card data passes through your systems |
The rows come from Stripe's PCI guide and the PCI Security Standards Council's FAQ of 28 February 2025, which clarified the script criterion that the revised SAQ A added for embedded forms. A build with us uses one of the first two rows by default. For the second, the payment page carries a Content Security Policy listing only the script sources it needs, and Stripe publishes the exact directives.
You can read any page's security headers with our free HTTP headers checker. Confirm which questionnaire applies with your payment provider before you file it.
Stripe's webhook documentation says an endpoint may receive the same event more than once, that events are not guaranteed to arrive in the order they were created, and that in live mode Stripe retries a failed delivery for up to three days. A handler written for the happy path can pay a seller twice or mark a refunded order as paid.
So the handlers we build check Stripe's signature, record every event ID they have processed, answer fast and do the work from a queue. We also add a nightly job that compares the app's payment records with Stripe's and flags any row that differs, before a customer or an accountant finds it.
If a bank holds your users' accounts, its Customer Identification Program sets the floor for what onboarding collects. The federal rule for banks, 31 CFR 1020.220, requires, with narrow exceptions, at least a name, a date of birth for an individual, an address and an identification number, which for a US person is a taxpayer identification number, before an account opens.
A partner bank can ask for more than that minimum, so we build onboarding from the partner's written requirements rather than from a template. The vendor runs the checks. Four things around them are product work, and we build them:
We do not write your AML policy or file reports with regulators. Your compliance lead and counsel own the policy; we build what it specifies and make its records easy to produce.
A lending MVP is judged on two outputs before anything else: the repayment schedule a borrower is shown, and the letter a declined applicant receives. We build the schedule from one tested calculation that the offer screen, the agreement and the servicing view all call, so the three cannot disagree. Our free loan calculator prints a full amortization schedule to check the build's numbers against.
For notices, Regulation B gives a creditor 30 days after a completed application to notify the applicant, and a denial must state the specific reasons or tell the applicant of the right to ask for them. We generate both from the decision record, so the reasons sent are the reasons the rules used.
Which disclosures your product needs, under Regulation B, Truth in Lending and the laws of the states you lend in, is for your counsel to set. We build the screens, letters and records they specify.
Money transmission in the US is licensed state by state, which is why the Conference of State Bank Supervisors drafted a model law, the Money Transmission Modernization Act; its page says 31 states have enacted it in full or in part. A startup without those licences builds on a partner that has them, and that partnership is where the risk sits.
Synapse Financial Technologies sat between fintech apps and their partner banks. According to the CFPB, it failed to keep adequate records of where consumers' funds were and to make sure its records matched the banks'. After it filed for bankruptcy in April 2024, the banks were found to hold $60 million to $90 million less than its records showed, and consumers went weeks or months without access to their money.
Our reading for anyone building a wallet: the balance on the app's home screen is a claim about money someone else holds. The partner's books are the record that counts. So a wallet we build includes a daily reconciliation that compares every user's balance in your app with the partner's own report and holds payouts when the two differ, so a gap is found in a day rather than in a bankruptcy filing.
The FTC Safeguards Rule covers financial institutions under the FTC's jurisdiction that no other regulator oversees under the Gramm-Leach-Bliley Act. Its examples include mortgage lenders, payday lenders, finance companies and wire transferors. Whether it covers your product is a question for counsel.
Where it does, the rule asks for a named Qualified Individual, a written risk assessment, encryption, multi-factor authentication, activity logs, regular testing and a written incident response plan. It also requires notice to the FTC within 30 days of discovering a breach of at least 500 consumers' unencrypted information. These are the controls a build with us writes into the system itself:
This page claims no PCI DSS, SOC 2 or ISO 27001 report for Digital Heroes. Those reports describe a company's own controls and come from an auditor, so ask any vendor that shows one for the auditor's name and the report date. Book an independent penetration test before launch as well; its findings go into the build team's next sprint.
The steps are the ones on our custom software development company page. What changes for fintech is what discovery has to produce, and whose name the provider accounts are opened in.
An MVP usually takes 8 to 12 weeks of build and a production platform 16 to 28. Our CTO, Divyansh Singh, owns the architecture, including which parts are bought from a provider and which are built. The engineers work from Delhi and Lucknow, and our New York headquarters replies the same business day, 9 AM to 6 PM Eastern.
Under our MSA, the code and designs made for your project are assigned to you on full payment, and the repositories and cloud accounts sit in your name from the first sprint. Our engineers are collaborators you can remove.
Our published ranges for custom software apply: a focused first version typically costs $40,000 to $150,000, and complex enterprise platforms $250,000 to $500,000 or more. A SaaS MVP, the shape many fintech first versions take, runs $30,000 to $80,000. Your own price is fixed after discovery, against the written scope.
Three costs sit outside any build quote, and a fintech budget that leaves them out is short:
For a rough figure before a call, our MVP cost calculator estimates build hours by feature, and the integration cost calculator estimates what each payment, identity or banking integration adds. The custom software development cost guide explains what moves a quote up or down.
We have not published a case study of a regulated fintech product, so this page does not claim one. Two client builds, shown with each client's permission, come closest: one takes payments, the other shows trainers what they have earned. Neither has a published results figure, so none is given.
PayFast checkout with its payment webhooks, proofs and production files with an order status history, transactional email, a browser design editor, CSV variable-data print jobs, and an admin panel with three roles. The stack is Next.js 15, React and TypeScript on Supabase.
The athlete and trainer mobile apps. Athletes find trainers and book sessions; trainers manage their schedule, send offers and follow their earnings. The apps use React Native and Expo, with Supabase behind them.
Clients rate our work 5.0 on Clutch from 66 verified reviews (checked 13 October 2026), and we have shipped work for clients in 40+ countries.
Several firms that rank for this search offer to build banking platforms. We do not, and saying so early is cheaper for both sides than a project that should not start.
It is building software that moves, stores, lends or verifies money: payment apps, wallets, lending platforms, investing tools and the onboarding flows that check who a user is. What sets it apart from other software work is that much of it runs on regulated providers, so the job is as much choosing and connecting those providers as writing code.
A focused first version typically costs $40,000 to $150,000, and complex enterprise platforms $250,000 to $500,000 or more. For a fintech product, add the provider fees, legal work and testing listed in the cost section, because none of them appears in a build quote.
Fraud, data breaches and money that users cannot reach. The clearest recent case is Synapse, where the CFPB says poor records left consumers without their funds for weeks or months after the company's 2024 bankruptcy. For builders the answer is design: hold as little sensitive data as possible, and reconcile your records against your partners' every day.
Fintech is a category, short for financial technology, not one company. It covers any business that uses software to deliver a financial service, from payment processors such as Stripe to bank data networks such as Plaid. Many companies carry the word in their names, so when a name is all you have, check the firm's registration before you trust it.
No developer can make you compliant; your business validates its own compliance every year. What we control is how much of the standard applies. With a hosted or embedded Stripe form, card numbers never reach your servers and the usual questionnaire is SAQ A rather than SAQ D. The card data section shows the four options.
No. The ledger of record stays with your bank or licensed provider. We build the product on top of it: the app, the onboarding, the records of what each user sees, and the daily job that checks those records against the partner's report.
You do. Provider accounts are opened in your company's name and billed to you, and the repositories and cloud accounts sit in your name from the first sprint. Under our MSA, the code and designs made for your project are assigned to you on full payment; we keep the reusable libraries and tools that existed before your project or were built for reuse.
Two weeks of discovery, then usually 8 to 12 weeks of build. Provider approvals often set the real date: a partner bank's review or a live account approval can take longer than the code, so we start those requests during discovery.
Last reviewed .
Tell us what the product does with money and who its partner bank or provider is, if you have one yet. After a 30-minute call you get a written scope and quote within 48 hours, and a fixed build price after discovery. Book 30 minutes with an engineer.
115 people across five studios in New York, Delhi, London, Sydney and Lucknow, shipping ecommerce, web, software and mobile work for founder-led brands. Senior engineers only, no account-manager relay, and the same team from kickoff to launch.
Co-Founder · Lucknow · 27 posts on the site
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