Fintech mobile · engineering partner
Fintech mobile app development company,
engineered for regulated products.
TrustChange delivers fintech mobile app development services for EU banks, EMIs, PSPs, neobanks and licensed crypto startups. We build the native iOS and Android apps, the backend for frontend, the authentication and SCA path, the payments and card integrations and the compliance controls as bespoke software under your brand — not a SaaS licence with a per-seat fee. You get a mobile product your team can extend, your users can trust and your auditor can read.
- EU-based engineers
- PSD2 & SCA aware
- PCI DSS scope kept small
- GDPR-aware storage
What "fintech mobile app" means here
Fintech mobile app development services without the SaaS strings
Most searches for a fintech mobile app development company return app studios that hand over pixels, or SaaS providers that license you a shell on a shared backend. We work the other way. TrustChange is a fintech mobile engineering partner: your brand, your data, your keys, your code. What you buy is engineering — a regulated mobile product built for your rails, your licence context and your close cycle.
Deciding whether to buy, build or wrap? Start with CTO advisory. The wider platform view lives on fintech infrastructure, and the web-and-app angle on fintech app development company.
Product surface
Three surfaces in every fintech mobile app development services engagement
A regulated fintech app is not one product. It is the native customer app, the mobile-optimised backend for frontend that mediates against your core, and the release and telemetry pipeline. We ship all three as one product, on one architecture, with one team accountable end to end.
-
01
Native mobile apps
iOS and Android apps under your brand: onboarding, KYC, accounts, payments, cards, statements, notifications and in-app support.
- Swift / Kotlin native
- Design tokens per tenant
- Push, deep links, biometrics
-
02
Backend for frontend
A mobile-optimised API layer between the app and your core: session, feature flags, screen assembly and rate-limited endpoints.
- Signed session tokens
- Feature-flagged rollouts
- Rate limits & abuse rules
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03
Release & telemetry
Store pipelines, staged rollouts, crash reporting, feature flags and analytics you own — no third party watching your users from the shadows.
- App Store & Play pipelines
- Staged & feature-gated release
- Self-hosted analytics
Stack
What sits behind our fintech mobile app development services
Eight layers, one system. Every layer names an owner, a control and a piece of audit evidence — nothing is left implied under the "mobile app" label.
Delivery patterns and evidence: how we deliver. Adjacent surfaces: wallet and custody engineering for crypto balances and on- and off-ramp integration for fiat legs.
| Layer | What we build |
|---|---|
| Client apps | Native Swift (iOS) and Kotlin (Android), driven by design tokens per tenant Same product surface, many brands — no shared multi-tenant backend behind it. |
| Authentication & SCA | Passkeys or password + step-up, biometrics, device binding and PSD2 SCA where required Exemption and step-up logic is engineered in, not left to the flow. |
| Backend for frontend | Mobile-optimised REST/gRPC layer with idempotency keys, retries and offline replay The core service stays untouched; the BFF absorbs mobile-specific concerns. |
| Payments & cards | PSP, card-issuer and open-banking integrations, tokenised card data with hosted fields PCI DSS scope is kept small; PANs never touch your servers. |
| Compliance controls | KYC/KYB, sanctions and device-risk screening, transaction limits, dispute intake Rules run before the money moves; every decision writes to the audit log. |
| Data & storage | GDPR-aware storage with EU regions, data map, retention rules and DSAR tooling Your DPO gets a working export path, not a promise. |
| Release pipeline | Store pipelines with signed builds, staged rollout, kill switches and rollback A bad build is halted at the store, not at the phone. |
| Runtime & delivery | EU-hosted backend, CI/CD, observability, crash reporting, 24/7 on-call Your identity provider, your keys, your data regions. |
User path
From cold start to confirmed transfer
Every meaningful action in the fintech mobile app goes through the same gates before it reaches your core. Speed comes from tuning the pipeline, not from skipping a step or trusting the client.
- 01
Open
Cold start
The app boots against a signed config; feature flags decide what the user sees today.
- 02
Auth
Biometric or step-up
Passkey or password with device binding; PSD2 SCA step-up runs where the rule applies.
- 03
Intent
User action
Transfer, card action, contract call or account change is captured with an idempotency key.
- 04
Screen
Sub-second
Sanctions, device-risk and transaction rules return a verdict; the reason is stored with the request.
- 05
Execute
Rail-bound
The BFF calls core services and rails; response is retried safely if the network drops.
- 06
Confirm
Immediate
Result posts to the ledger, an audit-log entry is written and a push notification reaches the user.
Delivery
How we deliver fintech mobile app development services
Five steps, in this order. Regulated mobile work runs inside the product backlog — no separate compliance phase bolted on before submission, no big-bang release of an untested fintech mobile app.
- 01
Scoping
Weeks 1–2
We map users, rails, licence context, store markets and the risk you must stand behind. Output: a scope, a control map and a costed plan.
- 02
Architecture
Weeks 3–4
Topology, auth model, BFF contracts, payment adapters and screening flow written down first. Regulatory constraints shape the design.
- 03
Build
Two-week sprints
Native app, BFF, payments and controls ship in slices. Each merge runs tests, static checks and a dependency scan.
- 04
Hardening
Before submission
Store-review dry runs, load work, failure drills and a third-party pen-test window. Kill switches are rehearsed with your staff.
- 05
Launch and run
Cutover + ongoing
Named engineers on 24/7 cover. Runbooks, dashboards, release playbooks and the audit log are handed to your team on day one.
Engagement
Four ways to buy fintech mobile app development services
Same engineers, same standard. Only the commercial shape changes.
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Fixed-scope build
A defined mobile product at a fixed price and date. Best when rails, markets and features are settled.
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Dedicated team
A standing squad with a lead. Best for long roadmaps and quarterly feature releases.
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Staff augmentation
Senior mobile engineers inside your team. Best when you already own the plan and need iOS or Android depth.
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CTO advisory
Architecture and buy-vs-build review before you commit. Best at the design stage.
Questions
FAQ: fintech mobile app development company
Six answers up front on scope, positioning, stack choice, compliance, release and support. Bring the rest to the call.
What do fintech mobile app development services cover in a TrustChange engagement?
We engineer a branded, client-owned iOS and Android app end to end: the native mobile surface, the backend for frontend, the authentication and SCA path, payments and card integrations, compliance controls, GDPR-aware storage and the store-release pipeline. It ships as source code in your repositories, with signing keys under your own Apple and Google accounts and the IP assigned to you.
How is your fintech mobile app development company different from an app-studio or SaaS provider?
An app studio builds a beautiful shell that later needs a fintech backend and controls bolted on. A SaaS provider licenses you a generic app on a shared backend and takes a cut. TrustChange engineers the app and the fintech spine together — auth, SCA, payments, screening, ledger, evidence — because a regulated mobile product fails on the seams between those things, not on the pixels. You keep every line of code and every control decision.
Native or cross-platform, and which technology stack do you use?
The reference build is native — Swift on iOS and Kotlin on Android — because cryptography, biometrics, background tasks and store-review compliance behave best on native platforms. Where a client prefers a shared codebase, we support Kotlin Multiplatform for shared business logic while keeping the UI native. React Native is on the table for scoped surfaces; we do not push it for the whole customer app in a regulated fintech product.
How do you engineer PSD2, SCA, AML/Travel Rule and GDPR into a fintech mobile app?
TrustChange is an engineering partner, not a law firm — your legal advisers and MLRO set the policy, we ship the controls and the evidence. That means KYC/KYB in onboarding, PSD2 SCA with exemption and step-up logic, sanctions and device-risk screening before money moves, Travel Rule data on crypto transfers and GDPR-aware storage with data mapping, retention rules and DSAR tooling. Nothing about licences or supervisor approvals is claimed on your behalf.
How do App Store and Play Store review, staged rollout and rollback work?
Store submissions run through signed pipelines with staged rollout on both stores, feature flags on the client and BFF, and a documented kill-switch and rollback path. A bad release is halted at the store or gated off with a flag, not left running on customer phones. Store-review edge cases (screenshots, IAP boundaries, content rating, crypto disclosures) are handled by an engineer who has done the submission before, not on the day the review lands.
Do you also run the fintech mobile app after launch, or hand it over?
Both are on the table. Most clients start with named TrustChange engineers on 24/7 cover during the first months while their own team ramps up, then take the platform in-house with runbooks, dashboards, store-release playbooks and the audit bundle. Some keep us on as a dedicated development team or on staff augmentation for feature-roadmap work, or as CTO advisory on architectural calls.
Book a discovery call for fintech mobile app development services
Bring the target markets, the rails, the licence context and the launch date. We come back with a control map, an architecture view and a costed plan for a fintech mobile product you own end to end. No demo theatre.