Fintech apps

Money apps people trust.

Banking, payments, investing and finance apps — secure onboarding, ledgers, cards and payments with the polish users expect from their bank. Free working prototype in 1 day, then a production release at a fixed price and date.

Web & Mobile apps

Get your free prototype 30-min call · no commitment

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TransferService.swiftAI

func send(_ amount: Money, to payee: Payee) async throws {

let key = IdempotencyKey()

try await auth.confirm(.faceID)

let tx = try await ledger.transfer(amount,

from: account, to: payee, key: key)

await notify(.sent(tx))

}

Senior review · approved

Pipelinemain

Build
Testsledger checks
Security review
Betainvite-only
App storeslive

Buildto launch

Day 1Week 1Week 2Week 3Live

Wallet 1.0 is liveTransfers in 2 secondsnow

At a glance

One product. One price, one date.

The essentials, before you book a call.

UDEX builds Fintech apps for founders and product teams. Banking, payments, investing and finance apps — secure onboarding, ledgers, cards and payments with the polish users expect from their bank. AI writes the code, tests and CI/CD, while senior engineers own the architecture and review every change.

1 dayFree prototypeNo payment, no commitment

FixedPrice and dateAgreed before we start

100%YoursCode, repository and accounts

Platform: Web and mobile fintech products
Ships to: Production
Stack: SwiftKotlinNext.jsStripePlaid
Quality: Senior review on every change, automated tests, CI/CD

How it works

Idea to production. In three steps.

AI does the heavy lifting. Senior engineers make every decision that matters.

01Day 0
Share the idea
A 30-minute call. We agree on the core flow, the scope and a fixed release date.
02Day 1 → release
AI builds, senior engineers decide
AI writes the code, tests and CI/CD. Senior engineers set the architecture and review every change. Your prototype is ready on day 1.
03Release day
Ship to production
The release goes live, and the code, repository and accounts are handed to you.

Who it’s for

Built for founders and product teams.

Here is where it works best, and where it doesn’t.

Neobanks and wallets

Accounts, cards and transfers in a polished app.

Payment companies

Checkout, payouts and merchant dashboards.

Lending products

Applications, decisions and repayments.

Personal finance

Budgeting, savings goals and insights.

Investing apps

Portfolios, orders and statements.

Companies adding finance

Embedded payments, cards or loans.

Not the right fit

Products that need their own banking licence before launch.
High-frequency trading engines.
Certified compliance from day one, such as HIPAA or PCI audits.
Open-ended hourly work without a defined first release.

How we work

Six stages, one team.

All services

Pricing

Start free. Ship at a fixed price.

Two steps. The prototype costs nothing, and the release costs exactly what we agree.

Prototype

Free1 day

A working prototype of your core flow to test with users and show investors.

Key screens and the main user flow
Working on real devices and browsers
No payment, no commitment

Get the free prototype

Release

Fixed priceand date, agreed upfront

A production release, shipped to production, that you fully own.

Swift, Kotlin, Next.js and the features agreed on the call
Automated tests, CI/CD and senior code review
Release to production and 100% code ownership

Start with a call

Fixed means fixed. No hourly billing and no surprise invoices: anything new is priced before it is built.

Book a call

Thirty minutes. Then your prototype.

Walk us through the idea, and we will scope the core flow and build your free prototype the next day.

Book a 30-min call

FAQ

Questions, answered.

Straight answers about cost, timing, quality and ownership.

How much does it cost to build a Fintech app?

The price is fixed for the agreed scope and set before work starts. You first get a free working prototype of the core flow in 1 day, then a fixed price and release date for the production version.

How long does it take to build a Fintech app?

A working prototype takes 1 day. The production release date is agreed upfront and depends on the scope; AI speed with senior engineering makes it much faster than classic development.

Do you work with banking partners?

Yes. We integrate with banking-as-a-service, card issuing, KYC and open-banking providers so you can launch without your own licence.

How do you keep money right?

With double-entry ledgers, idempotent payments, reconciliation and full audit trails.

Is it secure?

Security is built in: encryption, strong authentication, least-privilege access and security reviews before launch.

Is the prototype really free?

Yes, with no commitment. After a 30-minute call we build a working prototype of your core flow in 1 day, and then you decide whether to continue to the release.

Will the price go up during the build?

No. The price is fixed for the agreed scope. Anything new you want to add mid-build is priced separately and built only after you approve it.

Who owns the code?

You do, 100%. The source code, repository and accounts are yours, and the release ships to production under your name.

Is AI-written code safe to ship to production?

It ships only after senior review. Senior engineers own the architecture, security and code quality, and automated tests run on every change.

In practice