How to Choose a Software Company to Build Your Fintech Product

The right software company for a fintech product is one that has already built your kind of product and still runs it for real users. Fintech covers payments, lending, digital banking, brokerage and trading, crypto exchanges and compliance tools, and each kind needs different experience. So before you ask anyone for a recommendation, name the kind of product you are building.

Which software company should build my fintech product?

No list of names can answer this for you, because a list does not know what your product does, which licence it runs under or which partners you have signed with. A better question is which firms have built a product like yours, and whether it still works for real users today.

Most fintech products are built on top of a licensed company. Depending on the product, that is a bank that holds deposits, a card processor that moves card payments, a custodian (a firm licensed to hold assets for others), or a broker or exchange that carries out trades. The software company builds what sits around that partner, so the experience to ask for depends on the partner your product will rely on.

What does the software company build, and what does a licensed partner provide?

Here is how the work usually splits for the common kinds of fintech product:

• Payments and money transfers. A payment processor or a licensed payment institution moves the money. The software company builds your checkout or app, the connection to the processor, the ledger (your own record of every payment), and a daily check that this record matches the processor's reports. Ask the firm which processors it has integrated and how its ledger handles refunds, failed payments and duplicates
• Lending. A bank or a licensed lender usually funds the loans, and credit bureaus and data providers feed the decision. The software company builds the application flow, the decision rules, the repayment schedule and the process for chasing missed payments. Ask which credit data providers the firm has connected and how a change to the lending rules goes live
• Digital banking and wallets on a partner bank. The partner bank holds the deposits and issues the cards, often through a banking-as-a-service provider, a company that lets apps use a partner bank's licence and accounts. The software company builds the app, the onboarding and the records that must match the bank's records every day. Ask how the firm kept its records in line with the bank's in an earlier project
• Brokerage and trading platforms. A licensed broker, a clearing firm (which settles trades after they happen) or an exchange sits behind the trades. The software company builds the trading terminal, the order management system that tracks every order until it is filled, and the connections to exchanges and other trading venues. These connections often use FIX, the standard message format brokers and exchanges use to send orders. Ask which venues the firm has connected and which of its systems take live orders today
• Crypto exchanges and custody, which means holding customers' coins. In the EU and many other countries the operator needs its own licence or registration, and custody may be done in-house or by a specialist. The software company builds the matching engine that pairs buy and sell orders, the wallets and the deposit and withdrawal flows. Ask how the firm separates hot wallets, which stay online for fast withdrawals, from cold wallets, which stay offline for safety, and who can approve a withdrawal
• Proprietary trading firm platforms. The firm's broker or another trading partner executes the trades. The software company builds the evaluation challenges (the paid tests a trader passes to get a funded account), the trading rules and the record of each trader's balance and results. A good check is how a rule breach is detected and how fast it reaches the trader's account
• Compliance and onboarding tools. Identity check providers and screening providers, which check people against sanctions lists, do the checks. The software company connects them, builds the review queue and keeps the audit trail, a record of who decided what and when. Find out how a reviewer's decision is recorded and who can change it later

Many products mix two or three of these kinds. A wallet with a card and a savings product touches payments, banking and sometimes lending. Write down every kind your first version needs, and look for a firm that has built the hardest of them.

Why does the partner matter when I choose a software company?

Your partner sets rules that the software has to follow, and the software company has to know them. In June 2023 the Federal Reserve, the FDIC and the OCC issued joint guidance on third-party relationships. It tells a bank to plan, check, contract with, monitor and, when needed, end its relationships with outside companies, and it says these principles apply to fintech companies too, including those that deal with the bank's customers. In September 2026 the agencies proposed new guidance to replace it, so ask your partner bank which rules its oversight of you follows.

Records are where this goes wrong in practice. Synapse Financial Technologies, a company that connected fintech apps to partner banks, filed for Chapter 11 bankruptcy on 22 April 2024. Its records and the banks' records did not match, and the Chapter 11 trustee, former FDIC chair Jelena McWilliams, estimated the gap at 65 to 96 million dollars. End customers of several fintech apps could not reach their money for months. Ask any firm that will build your ledger how it proves every day that its numbers match the partner's.

Card payments come with a security standard of their own. PCI DSS, published by the PCI Security Standards Council, applies to every company that stores, processes or transmits cardholder data, and to systems that can affect the security of that data. Version 4.0.1 came out in June 2024. A good firm will often design your product so that card numbers never touch your servers, which shrinks the part of the system the standard covers. Ask the firm how it would do that for your product.

In the EU, a firm that runs a crypto exchange or holds clients' crypto-assets needs authorisation as a crypto-asset service provider under the MiCA regulation, whose rules for these firms apply from 30 December 2024. Banks and some other licensed firms can notify their regulator instead. Payment institutions need authorisation under the second Payment Services Directive (PSD2). Getting the licence is work for your company and its lawyers. The software company builds the records and controls the regulator will ask to see.

How do I check a fintech software company before I sign?

• See one system of your kind that is still running, and find out who uses it. A demo or a design file shows less than a live product
• Get a list of the licensed partners, processors or venues the firm has integrated, and which of those integrations it still supports
• Talk to an engineer who worked on that system. Have them walk you through how money moves through it and what happens when a step fails
• Find out how the firm records every movement of money and how it checks those records against the partner's
• Request security evidence in writing: who can get into the live systems and how that access is logged, where passwords and keys are kept, and who reviews each release before it goes live. A SOC 2 report, if the firm has one, is an attestation report by an independent CPA firm under AICPA standards. Ask whether it is Type 1, which looks at a single date, or Type 2, which covers a period, and which of the firm's services it includes
• Check the contract for code ownership, for the accounts your product runs on, and for what the firm hands over when the work ends

The article on dedicated teams, linked above, covers contract checks in more detail, including what to put in writing about code ownership.

What are the warning signs?

• Every kind of fintech product on the firm's list, and no live system it can show for yours
• An estimate nobody revised after reading your partner's integration documentation
• No clear answer about who keeps the records of money movements, or how they are checked against the partner's
• A claim that the firm's software comes “already compliant” or “pre-licensed”
• Security described with badges and logos instead of documents
• Code kept in the firm's own repositories and cloud accounts, with no date for moving them to yours

Where does amBrain fit?

“Trading terminal development, order management systems, and FIX protocol exchange integration.” is how amBrain describes its trading services.

amBrain builds crypto exchanges: matching engine, wallets, deposits and withdrawals. amBrain builds platforms for proprietary trading firms: evaluation challenges, trading rules and accounting. amBrain builds algorithmic trading infrastructure: order execution, market data and pre-trade risk controls. amBrain takes over projects that stalled with another team and brings them to production.

amBrain works in three formats: full delivery, a dedicated team, or engineers embedded in your team. The client keeps full ownership of the product and the code, except amBrain's reusable components. amBrain has been building software since 2019.

If you are building a payments, lending or digital banking product, that is outside the work listed above, so look for firms that have that kind of system running for real users. Ask amBrain the same questions as any other firm on your list.

Common questions

• Can one software company build any fintech product? Some can build several kinds, but ask for a live system for each kind your product needs, and check each one with the questions above
• Should I choose a white-label platform instead? A white-label platform, a ready-made product you put your own brand on, is faster to launch when your product works the same way as many others. A custom build makes sense when the way your product works is what sets you apart, and the article on starting a trading platform, linked above, compares the two
• Who is responsible for compliance, the software company or me? You are. Your company and your licensed partners answer to the regulator. The software company builds the records and controls you need, and you should agree in writing which of them it delivers