Project background

The team of 200+ members worked for a year on a project to deliver probably one of the biggest Flutter applications in the world.

The banking environment is on a constant quest for change. The pandemic and lockdowns even strengthened and sped up the technology revolution in this industry.

During COVID, 60% of the banks limited the availability of their offices, and 51% have built the process for setting up the account online, according to a recent study published in the Digital Banking Maturity 2020 Report.

The demand for digital acceleration forces the banking leaders and market challengers to compete with the most innovative tools in their web portals and mobile banking apps.

Mobile banking applications currently enable users to run the complex KYC process, send transfers, make investments, access more complex banking products like scoring and quick credits, and use loyalty programs.

Clients want to have their bank on their mobile devices. This new banking environment of 2022 has also inspired Credit Agricole Bank Polska to invest in building a new mobile banking application for its retail customers. "CA24 Mobile" app offers an entirely new quality of online banking services.

Our Client also made a huge organizational change in order to accomplish this project with the agile approach. They nominated a group of Product Owners responsible for the broad spectrum of their mobile banking app features represented by squads.

The development team consisted of 30 Flutter Developers working to build the next-generation iOS and Android mobile banking app. 

The development team consisted of 30 Flutter Developers working to build the next-generation iOS and Android mobile banking app. 

CA24 Mobile app is dedicated to retail customers. It’s probably the world’s biggest banking app in Flutter. An ultimate proof that the Flutter is enterprise-ready. Flutter proved to be ready for the delivery of a complex banking product.

Banking industry

Today's most robust trend in the banking industry is the shift to digital, specifically online and mobile banking. Major banks across the globe are releasing new features in their mobile banking applications to attract new customers and retain the existing ones.

In today's era, customers get used to having more and more services at hand. People want to save time and shorten existing processes. Most of them avoid visiting a physical bank branch to handle their transactions or use other banking services.

64% of mobile banking users claim they would research a bank's mobile capabilities before opening an account, and 61% say they would change banks if their bank offered a poor mobile banking experience. In response to this, in 2020, 34% of banks implemented fully digital processes.

Nowadays, offering banking services via a mobile app and online isn't optional anymore. Banks need to provide various features and benefits – such as, for example, the fully digital process of account opening, chatbots with advanced use cases, applying for a credit card or loan, discount offers, remote authentication, and more – to attract and keep customers.

Credit Agricole Bank Polska decided to become one of the leaders in digital banking. Their new application, CA24 Mobile, offers a unique customer experience and user interface on the Polish market. It is a secure mobile banking app that provides a complete variety of features that will be further developed. As a result, customers can manage their finances faster and, of course, more conveniently - entirely remotely.

One of the most significant distinguishing features of the app, in addition to the Flutter technology itself, is the Benefits Club. These proposals are selected and adjusted individually for each client. Currently, there are over 1,400 offers. Customers can quickly redeem their discounts via the app.

Shortening the time-to-market has been identified as the highest priority for product managers from banking institutions according to our Raport on Mobile Banking Apps.

Sign up to get the eBook about Flutter in Banking!

Scope of work

This project proves that Flutter is ready for large-scale enterprise applications.

When Credit Agricole Bank Polska was looking for the technology to deliver its brand-new consumer banking application, several cross-platform technologies were considered. 

Flutter proved to be the most efficient when it comes to the speed and ease of using complicated UI to meet the requirements of the complex design system prepared for the banking application.

The scope of work was divided into 12 squads, with different teams being responsible for selected parts of the customer journey. Two squads were non-functional and were intended to prepare the work for other teams.

The framework squad was responsible for the overall application architecture, selection of different tools, and performance of the application.

The Design System squad was preparing the atoms and components for other Flutter Developers to use while implementing different interfaces.

Our team operated in a tightly regulated environment, taking care of the complex delivery process, which was using several different environments.

The noteworthy is that our team operated in an environment with different stakeholders, as other companies were involved in facilitating the mobile application development and providing the backend, infrastructure, and test-related services.

Thanks to the agile culture of work, all teams worked united around the same goal to deliver the best possible mobile banking application. In addition to the Agile strategy, the project also supported the idea of modern microservice architecture.

As LeanCode we were leading the Flutter chapter consisting of 25 Flutter Developers.

Value delivered by LeanCode

LeanCode was participating in building one of probably the biggest Flutter mobile application in the world. Our team of 14 Flutter Mobile Developers supported Credit Agricole Bank Polska with:

Advanced Flutter Expertise

System Architecture

Design System Implementation



Opening Bank Account

Biometric Authentication

Product Management

River of Benefits

With the Know Your Customer (KYC) process this banking mobile app enables customers to open the regular, forex, and savings accounts in a quick and secure way. Customers can confirm their identity via mobile phone. KYC is an obligatory process meant to prevent banks from being used, by criminal elements for money laundering activities.

User Experience design

One of the most important areas of developing a mobile banking application was meeting the challenging UX requirements set by the bank. 

The CA24 Mobile application was created from scratch following the User Experience created by Efigence, the Design Studio. LeanCode’s role was to implement the UX in the Design System, which ensured the integration of the different parts of the mobile banking application.

The central place of this mobile banking app is the product management area. It consists of product cards known as the Accordion, which are the dashboard's main part. The user can switch between them by swiping up and down. In the next phases, the cards' personalization will be introduced.

The cards contain basic product data and static buttons directing to specific functions (e.g., transfers) and dynamic buttons displaying incentives to use products and services. Dynamic buttons are controlled by the CRM system, serving personalized offers.

Managing the bank's offers and services was another challenge we faced as part of the project. The aim was to interest the user while avoiding the user's weariness. The bank decided to disperse the placeholders.

Offers appear in various places of the application - as subtle suggestions, but also dedicated product ghost on accordion cards (a card that suggests a product that the user can purchase).

Following the atomic design principles, we've created the shared library of design system components which were reusable between the screens.


Support Portal


Online Cash Loan Request

Runtime Application Self-Protection

The support portal allows you to contact a bank consultant using a chat or phone connection. When calling the call center via the application, the user bypasses the standard stages of identification on the hotline, and in the case of some processes (credit, account creation). In the support portal, there is also a map with the nearest bank branches, ATMs, and CDMs.

Review of our work

Credit Agricole logo

LeanCode has delivered the MVP within 2.5 months, exceeding our expectations. Agile and detail-oriented, they've taken the time to understand the banking industry to deliver the most effective solution for our users. They are professional, efficient, and responsive.

Tomasz Czerwiński
Tomasz CzerwińskiDeputy CIOCredit Agricole Bank Polska

Awards & press releases

Cashless logo
"Credit Agricole Bank Polska implements the next-generation application. Among the new features, there will be requests for a Blik transfer and payment for highways. The new app will also enable the opening of personal accounts by customers who have not been Credit Agricole's clients and include tools to facilitate personal finance management."
Fintek logo
The "CA24 Mobile - full of benefits" application has a new user interface with navigation elements such as accordion cards - on the first screen, users will find the essential information, a pull-out drawer with transaction history, or a bottom menu that breaks the usual patterns. New customers can also open an account with Credit Agricole Bank Polska remotely using biometrics.

Other projects

Case Study of Invoice Gateway App
Invoice Gateway logo
Web Application

Invoice Gateway

Case Study of Kontomierz app
Kontomierz logo
Web Application


Case Study of Welliba App
Welliba logo
Mobile & Web Application


White Paper: Flutter for Enterprise

How do we handle mobile app development?

Concept Exploration
Proof of Concept
Product Design
Agile Development
Maintenance and Support
Meet our expert

Let's schedule a 20 minute talk

Łukasz Kosman CTA Biznes

This is the initial scoping call. Its purpose is to get a better understanding of what you want to build. After this call, you will have an idea about your project's feasibility and the ballpark estimates.

Łukasz KosmanCEO at LeanCode