Payments
Stripe Connect platforms, marketplace payouts, ACH and card rails, tokenized PAN handling, dispute and refund flows. We have shipped a merchant payment processing platform end to end, including the operator console.
Industry pillar
Fintech software development partner. Built four production fintech platforms since 2020.
We build custom fintech SaaS for founders and CTOs who need a partner that has actually moved money through the rails before. Payments, lending, trading, business finance. Tampa-based agency. Clients in Boston, Phoenix, and Tampa.
4
Production fintech platforms shipped since 2020
3
US states with active fintech clients (FL, MA, AZ)
10-16w
Typical fintech MVP timeline, kickoff to live
2020
First fintech engagement; consecutive years since
The short version
Most fintech failures are not engineering failures. They are partner-rail decisions made before the engineering started. We have shipped four fintech platforms since 2020, picked the wrong rail on one, and learned from it. The four sections below are how we work with fintech founders so you do not have to learn the same way.
What we build for fintech founders
Six fintech surfaces, all of which we have shipped at least once in the last five years. Each has a payment-network, regulatory, and operator-tooling shape worth knowing before you scope.
Lending
Loan origination, underwriting workflows, lender-borrower marketplaces, repayment schedules, KYC/KYB. Our dental-financing platform connects practices, patients, and lenders in a single transaction flow.
Trading
Real-time market data, order routing, account dashboards for retail and institutional users, audit logs that satisfy a regulator. Our trading-experience platform serves both audiences from the same codebase.
Business finance
Accounts payable and receivable, ledger reconciliation, expense workflows, multi-entity reporting. We shipped a financial-management product for SMBs that replaced a spreadsheet stack.
Cross-border + FX
Multi-currency ledgers, exchange-rate sourcing, settlement timing. The hard part is not the code, it is the operational truth: which rate, at which moment, for which leg of the transaction.
Compliance + RegOps
Audit logging, role-based access, data retention policies, exception queues for compliance teams. We design these as first-class features, not as something to layer on before an audit.
Why DesignKey for fintech
What we believe about building fintech the right way
01
We have shipped fintech for real money flows
Four production fintech platforms across payments, lending, trading, and business finance. Not pilots. Real users moving real money. The case studies below name the work.
02
We pick the rail to match the unit economics
A founder once asked us to integrate Stripe Connect because their advisor recommended it. We pulled their transaction profile, ran the math against Dwolla, and saved them eight basis points on every transfer. The right answer depends on your numbers, not on what is trendy.
03
Tampa rates, US-time-zone delivery, no offshoring
Our blended rate is roughly 30 to 40 percent below NYC, SF, and Boston fintech specialists for equivalent senior engineering. Same time zone as most of the East Coast. Same English. Same compliance literacy.
04
We say no to scope we cannot back up
We do not hold money-transmitter licenses. We do not sponsor BaaS programs. We do not write your compliance memos. We build the software layer on top of partners who do those things, and we say so up front instead of taking the engagement and figuring it out later.
05
Senior-only engineering, no junior pass-through
Every engineer on a fintech engagement has shipped a regulated product before. We do not staff fintech work with bootcamp graduates because the cost of a mistake at the payment layer is permanent.
06
We instrument your unit economics from week one
Transaction success rate, average ticket size, partner-fee leakage, dispute rate. We wire these into a dashboard you actually look at before the launch, not as a follow-on engagement.
Case studies
Four fintech platforms we shipped
Each was a real engagement with real users moving real money. Three are named clients. One asked to stay unnamed. The work is documented either way.
How a fintech engagement starts with us
Three steps before any code. Skipping them is how fintech projects fail.
- 1
Rail decision review
We sit down with your transaction model and walk through Stripe, Adyen, Marqeta, Dwolla, Plaid, and the direct-bank options. The fee math, the settlement timing, the dispute exposure. The decision affects everything downstream and most founders are too far in by the time they realize. Two-hour session, no commitment.
- 2
Regulatory surface map
Which licenses you need or who sponsors them. PCI scope. State money-transmitter exposure. Privacy posture (GLBA, state-level data laws). We do not write your compliance memos. We map the surface so your lawyer's bill is shorter and your build does not pretend the regulation does not exist.
- 3
Operator-tooling spec
The dashboards your ops team will use on day one. The dispute queue. The exception report. Most fintech MVPs forget these and then have to ship them in panic at week 10. We design the operator surface up front because that is what determines whether your team can actually run the product after launch.
Related services and deeper guides
Fintech work touches every layer of the stack. These pages dig into the parts that matter most for a fintech build.
FAQ
Fintech development questions, answered
The questions we get from founders and CTOs evaluating a fintech build. Pulled from real discovery calls in 2026.
Building fintech in 2026? Let's talk.
No sales pitch. A working session on your payment rails, regulatory surface, and operator tooling. We share what we have shipped and where we have failed. You decide if we fit.
Schedule a fintech discovery call