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Flutter Fintech App: Why Google Pay and Nubank Used Flutter to Rewrite Their Apps



June 24, 2022


June 24, 2022

The number of mobile Fintech app users has crossed hundreds of millions across the world and it is estimated to grow by several hundred million in the upcoming years. As most of the devices run on the Android and iOS operating systems, the majority of developers release their applications for both platforms. 

However, building native Fintech applications for Android and iOS can be time-consuming and costly, in contrast, building a cross-platform app can save lots of time and money if developed with the right technology.

In this post, we are going to highlight the benefits of the Flutter cross platform and why Fintech applications such as Google Pay and Nubank are rewritten using Flutter. 

Well, before that let's understand briefly about Flutter.

An overview of Flutter

Flutter is a software development toolkit for building mobile, desktop, web, and embedded applications from a single codebase. It was created by Google and was first released in May 2017.

The technology uses the Dart programming language introduced by Google and works in the Dart virtual machine with the JIT compiler. This allows faster code compilation and “hot reload” which automatically modifies the source code and injects it into the running application. 

Flutter amplifies this feature by supporting hot reload for the stateful components, so the changes in the source code can be immediately seen in the running application without restart. 

The technology is used by the top companies which include Abbey Road Studio, Google pay, and Alibaba Group and there are a half-million applications that use Flutter technology for app development.

Why Fintech giants like Google Pay and Nubank have rewritten their applications with Flutter

During the pandemic, the demand for Fintech applications has skyrocketed and it will continue to grow in the future. These apps provide services such as wealth management, budgeting, investments, online payments, insurance, and more. 

Google Pay and Nubank have a million users worldwide, and to provide seamless services to the growing iOS and Android users, they need reliable technology that can save their development time and cost without sacrificing the app quality.  

Let's have a look into the business requirements that led Google Pay and Nubank to build a cross platform Flutter Fintech app. 

Google pay Flutter app

The app serves dozens of countries and allows users to pay, manage expenses, and more online. 

Business requirements:

As the business requirements started to increase in the terms of users and app features, scaling up the app in the new countries with the 1.7 million lines of code was tough. In such a case fulfilling app requirements didn’t seem to be sustainable.

To make things worse, the new regions had maximum numbers of iOS users in contrast to existing users with Android systems, mostly in Asia. That means they would now require to build each feature twice for Android and iOS as well. 

So they decided to invest in cross-platform development with Flutter to achieve the goal in minimum time.

Nubank Flutter app

Nubank is the largest independent digital bank in Latin America providing financial services to 48 million users by 2021. Its headquarter is located in São Paulo, Brazil, and has its offices in Berlin, Germany, Buenos Aires, Argentina, and Mexico.

Business requirements:

The company aims to take banking to everyone using cloud technology. To expand the business rapidly they needed a way to quickly ship the final product to both Android and iOS users without sacrificing the application quality. 

However, the organization struggles to find enough native app development specialists to bring their idea into reality. As a result, their Android and iOS teams failed to launch the features in synchronization with each other. Moreover, during native app development, writing each feature twice seems to be a waste of time. 

Finally, Nubank concluded to have a single team who built the app for both Android and iOS using a cross-platform development approach. So, the only thing they need to find is the right technology for cross-platform development.

A wise move with Flutter cross-platform:

Nubank investigated several hybrid technologies including Kotlin, React Native, and Flutter. The goal is to evaluate the best solution that helps their teams to achieve the desired goal using a single technology with the long-term support, and convenience of use. 

They discovered that developers love Flutter as compared to the other options. It offers better features, strong documentation, and highly stable APIs. 

Similarly, In the case of Google pay, the team found out Flutter can enable resource-efficient scaling around the world. So they decided to choose Flutter.

The result of Flutter implementation in Fintech

Flutter has proven to be the game-changer for both Nubank and Google Pay.


On average Flutter, pull requests take 9.9 minutes to merge, compared to the average of 70.45 minutes on all platforms. Also, it gives the ability to major the app size by the feature of packages and correlates the metrics with the other system.

  • With Flutter Nubank launched its new life insurance feature in just three months.
  • It's an experimental developer tool built with Flutter Desktop that helps to reduce laptop battery usage by sleeping emulators.
  • With Flutter Nubank’s merge success rate was 30% better than its native platforms.
  • Flutter gives the Nubank app more UI consistency.
  • A tool that helps to dynamically deliver new content to the app allowing to localize new content without releasing a new version.

Google Pay

The rewritten Google pay app is much smaller and highly efficient to manage and update. 

  • The new code base is 35% smaller than the original one despite adding multiple features.
  • Saved 60 to 70% of the engineer's time as Flutter is too easy to manage. 
  • The app can scale quickly and efficiently across iOS and Android for the new version launch.

After looking into the implementation result of Flutter in the Nubank and Google Pay apps, it is clear that Flutter is the most promising technology when it comes to cross-platform application development.

In terms of code security, it is safer than native solutions. A native app can be reverse-engineered even after the code obfuscation however in the case of Flutter reverse engineering makes no sense as the source code is compiled into the native code and it is not readable to humans.

Bottom line:

From the article, we can conclude that Flutter has gained much fame in the world of cross-platform app development, and modern Fintech firms are more interested in Flutter due to its faster app development capabilities, simplified testing, high code security, and easy code management. 

So if you are building a Fintech application with Flutter bring it to DhiWise- A ProCode/LowCode web and mobile app development platform for developers. 

With DhiWise you can start building your Flutter app without worrying about the app design, as it comes up with the prebuilt app design templates and screen library. If you are building an app for banking applications like Google Pay or Nubank, use the following customizable templates. 

  1. Banksy- Digital Banking App UI Kit
  2. Safebank Mobile Banking App UI Kit

Moreover, the platform provides you with everything to speed up your Flutter app development for both Android and iOS. 

Get familiar with the DhiWise Flutter app builder and sign up now to start using it now!