# Banking Software Development

> Build digital banking platforms with core banking, mobile apps, fraud detection, and open banking APIs.

Canonical: https://app369.com/industries/banking/

Banking software for institutions modernizing legacy systems: digital onboarding, account and payments features, and mobile banking apps, designed with PCI DSS and SOX controls in mind from the start.

[**Get a Free Quote **→](https://app369.com/contact/) [**View Portfolio**](https://app369.com/portfolio/)

**PCI DSS**

and SOX compliance

**FL**

Based in Miami, Florida

**Flutter**

iOS, Android & web

**Fixed**

Price in writing before work starts

What App369 Delivers

## **Banking Solutions We Deliver**

01

### **Core Banking Platforms**

Modular core banking systems supporting deposits, lending, and treasury operations with real-time transaction processing.

02

### **Mobile Banking Applications**

Cross-platform mobile banking apps with biometric authentication, real-time notifications, and P2P transfers.

03

### **Fraud Detection Systems**

ML-powered transaction monitoring that analyzes behavioral patterns, geolocation, and device fingerprints in real time.

04

### **Payment Processing Engines**

High-throughput payment gateways supporting ACH, wire transfers, real-time payments (RTP), and SWIFT messaging.

05

### **KYC/AML Automation**

Automated identity verification, sanctions screening, and suspicious activity reporting workflows.

06

### **Open Banking APIs**

PSD2-compliant API layers enabling third-party integrations, account aggregation, and embedded banking services.

How it works

## **The Development Process**

Short sprints with a working demo at the end of each one mean you see progress early and can change priorities before they become expensive.

2. 01 ### **Discovery** Simon analyzes your vision, goals, and competitive landscape to craft a solution roadmap. This phase typically runs 1-2 weeks and defines the full project scope.
3. 02 ### **Design** Intuitive UI/UX crafted with interactive prototypes. Prototypes let you test the flow with real users before any code is written.
4. 03 ### **Development** Expert engineering using Flutter, Vue.js, Node.js, and GCP in 2-week Agile sprints with weekly milestone demos for full transparency.
5. 04 ### **Launch & Support** Reliable deployment with crash and uptime monitoring and ongoing maintenance. Maintenance plans run during business hours, Monday to Friday.

## The Technology Stack

- Flutter
- TypeScript
- Node.js
- GCP
- Firebase
- Vue
- JavaScript
- Python

Questions

## **Frequently Asked Questions**

### **How do you ensure PCI DSS compliance in custom banking software?**

PCI DSS controls span all 12 requirement categories, including network segmentation, encryption of cardholder data at rest and in transit, access control, and continuous monitoring. Sensitive data is tokenized using hardware security modules, and we conduct quarterly vulnerability scans and annual penetration testing as required by PCI DSS v4.0.

### **Can custom banking platforms integrate with legacy core banking systems?**

Yes, we build integration layers using API gateways, message queues, and adapter patterns that bridge modern applications with legacy mainframe and AS/400 systems. Our approach enables a gradual strangler-fig migration strategy rather than a risky big-bang replacement. We support ISO 20022 messaging, SWIFT connectivity, and real-time event streaming to ensure reliable data flow.

### **What fraud detection capabilities can be integrated into banking applications?**

Fraud detection systems use ensemble ML models trained on transaction velocity, geolocation anomalies, device fingerprinting, and behavioral biometrics. The system generates risk scores in under 100ms per transaction, enabling real-time decisioning without degrading user experience.

### **How does open banking API development work for regulated institutions?**

Open banking APIs are built compliant with PSD2, Open Banking UK, and FDX standards, supporting account information services (AIS) and payment initiation services (PIS). APIs are secured with OAuth 2.0, FAPI-compliant authentication, and certificate-bound access tokens. Our implementation includes developer portals, sandbox environments, and rate-limiting infrastructure for third-party onboarding.

![Simon Dziak - Founder of App369](https://app369.com/.netlify/images?w=120&h=120&fm=webp&q=100&url=%2Fimages%2Fszymon.jpg)

Your Development Partner

## [Simon Dziak](https://app369.com/about/)

I build every banking software development project myself, with Flutter and Firebase, and I personally ensure every project meets the highest standards.

## **Prefer a fixed price?**

Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.

- [**Web App MVP Sprint**from $6,000A scoped web app MVP in Vue/Nuxt or React, with a fixed quote after a $450 written scoping.](https://app369.com/fixed-price/web-app-mvp/)
- [**App Fix Ticket**from $450One reproducible bug in an existing mobile or web app, diagnosed and fixed.](https://app369.com/fixed-price/flutter-firebase-bug-fix/)
- [**AI Feature or Agent Build**$2,500One LLM feature or agent wired into your app or tools, with an eval set that shows how well it works.](https://app369.com/fixed-price/ai-feature-development/)

## **Build Secure, Compliant Digital Banking Platforms**

[**Get a Free Quote **→](https://app369.com/contact/) [**View Portfolio**](https://app369.com/portfolio/)