Working in the fintech industry can be highly challenging and demanding for engineers. The pressure to perform at a high level is constant, and mistakes are bound to happen sooner or later. To shed light on the real-life challenges faced by engineers in the fintech space, a group of professionals has shared their insights to provide a comprehensive look at what not to do and serve as valuable lessons for aspiring and seasoned engineers alike.

Coding errors or nightmares that engineers in the fintech industry might encounter.

1. Decimal precision errors

Fintech applications often deal with financial calculations involving decimal numbers. If the code does not handle decimal precision properly, it can result in incorrect calculations, leading to financial losses or incorrect statements for users.

2. Security vulnerabilities

Fintech systems handle sensitive financial data, so security is of utmost importance. If engineers overlook security best practices, it can lead to vulnerabilities such as SQL injection, cross-site scripting (XSS), or insecure API endpoints, potentially exposing user data to unauthorised access or malicious attacks.

3. Handling edge cases

Fintech applications often need to handle a variety of edge cases, such as unusual transaction scenarios or complex regulatory requirements. If the code does not account for all possible scenarios, it may lead to unexpected behaviour, regulatory compliance issues, or financial inaccuracies.

4. Inadequate error handling

When processing financial transactions, it's crucial to have proper error handling mechanisms in place. If the code lacks adequate error handling, it may fail to handle exceptions gracefully, resulting in system crashes, incomplete transactions, or incorrect data storage.

5. Slow or inefficient code

Fintech applications often deal with large volumes of data and require high performance. If the code is poorly optimised, lacks proper caching mechanisms, or inefficiently handles database queries, it can lead to slow response times, degraded user experience, or system failures during peak loads.

6. Integration challenges

Fintech systems typically need to integrate with various third-party services, such as payment gateways, banks, or regulatory APIs. Integration errors, inconsistent data formats, or compatibility issues can cause data inconsistencies, transaction failures, or regulatory compliance problems.

7. Compliance and regulatory issues

Fintech companies need to adhere to various regulations, such as anti-money laundering (AML), know-your-customer (KYC), or data protection laws. Failure to implement proper compliance measures or updates can result in legal consequences or reputational damage. 

It's important to note that these examples are not exhaustive, and real-life coding errors or nightmares can vary significantly. Engineers in the fintech industry need to be diligent, pay attention to detail, and follow best practices to ensure the stability, security, and accuracy of their systems.

Pieces of advice from engineers in the fintech space 

• Rewrite without changing meaning 

When working on code in the fintech industry, it's essential to make improvements and enhancements while ensuring the intended functionality and behaviour remain unchanged. This approach allows for code optimization, refactoring, or re-architecting without introducing new bugs or unintended consequences. By preserving the original meaning, you can mitigate risks associated with financial operations and maintain the integrity of your system.

However, it's important to note that rewriting code should be done judiciously and with a clear purpose. Complete rewrites can be time-consuming and introduce new risks if not properly managed. Before embarking on a code rewrite, it's crucial to analyse the scope, impact, and potential benefits of the rewrite, considering factors such as the size of the codebase, project timeline, and availability of resources. 

• Careful evaluation of the trade-offs and potential long-term benefits.  

It's advisable to involve team members, stakeholders, and industry best practices during the decision-making process to ensure that the rewrite aligns with the project's goals and requirements.

Learning from the experiences shared by engineers in the fintech space can provide valuable insights and help you navigate the challenges and complexities associated with high-profile engineering roles in the industry. 

• Code review with a focus on edge cases 

Code reviews are an essential part of the software development process, helping identify and fix potential issues before they cause problems. In the fintech domain, where accuracy and security are paramount, focusing code reviews on edge cases can be particularly valuable. 

Edge cases refer to scenarios that fall outside the typical or expected inputs, such as unusual transaction scenarios or regulatory exceptions. By dedicating extra attention to these edge cases during code reviews, engineers can identify potential pitfalls, ensure that the code handles all scenarios correctly, and mitigate the risk of errors that could impact financial operations or compliance. 

• Use a comprehensive testing suite 

A comprehensive testing suite includes unit testing, integration testing, functional testing, performance testing, security testing, edge case testing, and regression testing. Each type of testing plays a vital role in validating different aspects of the application, from individual components to system-wide interactions.

By prioritising comprehensive testing, engineers can minimise the likelihood of coding errors that could lead to financial losses, compliance issues, or reputational damage. It allows them to deliver robust and reliable fintech solutions that meet the high standards of the industry.

As the fintech industry continues to grow and evolve, engineers must navigate the complexities of developing robust and secure systems. Learning from the experiences and mistakes of others can be invaluable in preventing similar pitfalls. The shared stories from engineers in the fintech space highlight the importance of precision, security, compliance, and performance in fintech applications. Whether it's avoiding decimal precision errors, prioritising security, handling edge cases, or synchronising timestamps, these lessons emphasise the critical aspects that engineers must consider when building fintech solutions. By embracing these insights and best practices, engineers can minimise errors, deliver reliable software, and contribute to the advancement of the fintech industry as a whole.