Fintech Enhances Payment App with Clean Code Solution

Financial transfer app had bugs resolved, with performance and efficiency gains through clean code development


A global fintech was facing critical bug issues in its new app, a platform designed for financial transfers.


The act digital team worked on the clean code development of the app: functionalities and characteristics that were correct were retained, and the rest were rebuilt.


With the implemented corrections, the number of bugs identified in regression tests reduced by 90%, with optimized correction time, decreasing from two weeks to one day.

Technology and the intensive use of applications have brought dynamism to the financial sector. In this context, security and trust in conducting transactions have become even more relevant, being competitive factors for fintechs.

With plans to launch a new payment app, available for real-time transactions in more than 180 countries, a global fintech identified that the occurrence of bugs in the platform was excessive, compromising important application functionalities. To address this issue, the company hired act digital, which worked on the analysis and correction of flaws and the release of new versions of the system.

Faced with this challenge, the team identified that the best approach would be to perform clean code development, an approach where source codes are written in a clear, readable, and efficient manner. The goal of this procedure is to have code that is easy to understand and maintain, promoting simplicity, modularity, and the absence of unnecessary complexity.

By adopting this approach, the team maintained the original proposal of the tool, preserving aspects that were functioning well, but rebuilt points that were causing critical failures. This allowed for structuring a more reliable and effective application for international financial transactions, contributing to the sustainability and continuous evolution of the project.

After the implementation of clean code development, regression tests recorded a 90% drop in the number of bugs, generally related to visual aspects that no longer impact functionalities and transactions. In addition to restoring confidence in the platform, the promoted corrections established a secure foundation for maintenance and continuous improvements.


Client: Payments Finetch

With the capacity to process billions of dollars annually, the global fintech offers secure payment solutions for individuals and businesses. The company’s priority is to deliver reliable, scalable products aligned with the strictest compliance standards.

Among the solutions developed by fintech is a platform for payments, disbursements, and international remittances, benefiting users in more than 180 countries, reaching around 90% of the world’s population. The feature, which has processed more than $10 billion in remittance transactions, was enhanced with the support of act digital, addressing bug fixes and improving stability, performance, and continuous platform evolution.

Challenge: Bug Fixes and Critical Failures

The main challenges that the global fintech was facing before the launch of the app for international financial transactions were the high occurrence of bugs and critical failures. The highlighted problems were complex, resulting in low confidence. This also made the correction process long and inefficient, with a succession of bugs.

To launch the app, it would be necessary to fix all these points, reducing the number of bug occurrences, the recurrence of failures, and the resolution time of the problems. In addition to restoring confidence in the app, these improvements were crucial to streamline the release of new versions, ensuring an efficient process of continuous improvements.

Solution: Clean Code Development

Based on the problems presented by the app, the act digital team identified that it would not be feasible to fix each bug individually. The most effective and efficient procedure, in the case of this project, was to work on the development of the entire app, through refactoring and the use of clean code programming.

Refactoring, the procedure of altering and improving existing codes, was planned to maintain some views—components representing the user interface (UI) of an app. In this case, views that did not present problems were reused.

The proposed solution considered the need to reduce bugs as an essential process to improve reliability in the app. Through refactoring and clean code programming, critical failures would be fixed, resulting in an overall system performance improvement, as well as simplifying necessary maintenance and delivering new versions of the app.


The solution found was to refactor the entire application, focusing on achieving three objectives:

1 - Deliver a cleaner architecture, facilitating bug resolution without dealing with immense files.

2 - Create reusable components throughout the app, extending bug resolution in a component to all parts where its use was necessary.

  1. -Perform unit and integration tests to ensure that fixing a bug or adding a new feature does not affect the rest of the application.

Applied Technologies

The clean code development and refactoring processes adopted to solve bug problems were followed using the same technologies originally employed in creating the application:

  • Swift/SwiftUI for iOS
  • Kotlin for Android

The use of the same technologies was a resource found to reduce project delivery and learning time. However, the team practically rebuilt the entire app through refactoring, starting a new project from scratch and reusing only some of the views.

Results: Reliability, Bug Reduction, and Increased Efficiency

The delivered solution managed to restore confidence in the system for secure financial transactions. In addition to reducing bug occurrences, the found flaws became less complex, generating a low impact on the platform’s functionality and performance. Consequently, the time to correct flaws and release new versions was also shortened.

Key results obtained:

  • Cleaner and simpler code to work with due to the complete app refactoring.
  • 90% reduction in bug occurrences identified by regression testing.
  • Lower complexity in presented flaws and bugs without compromising system reliability.
  • Reduced bug correction time, from two weeks to one day.
  • Increased agility for delivering new versions (on average, one day).
  • Gained user confidence and credibility in using the application.

How Act Digital Can Help Your Company

act digital has been contributing to the digital transformation of the financial system, offering innovative solutions for fintechs and companies in this segment. With a team of specialists in the field, we conduct projects that deliver agile, secure, and integrated results aligned with market demands.

Explore the resources and technologies we employ in the financial segment:

- Platform Development: Creation and enhancement of financial platforms, including the development of robust and scalable systems to support operations such as financial transactions, account management, and other essential functionalities.

- Legacy Systems: Modernization and maintenance of systems that depend on older infrastructure, ensuring they remain functional, interoperable, and secure.

- Data and Operations Security: Strategies and technologies to protect sensitive data, prevent fraud, and ensure the integrity of financial operations. This includes implementing cybersecurity practices, advanced encryption, multifactor authentication, and strict compliance with industry regulations.

- API and Applications: Solutions focused on connectivity and improving the user experience. Efficient integration between different financial systems through APIs is crucial for facilitating interoperability. Additionally, developing intuitive and secure mobile applications provides access to offered financial functionalities.

Clean code development was the solution found by the act digital team to reduce bug occurrences and restore confidence in an app focused on international financial transactions. Do you want to improve the confidence, security, and efficiency of your digital solutions? Contact our specialists.

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