Unlocking Potential With Mobile App Performance Testing

Approximately one-fourth of all downloaded applications (25.3%) are used only once. The primary reason for this is their failure to meet user expectations. Issues such as technical glitches, excessive file size, and confusing user interfaces often lead to app removal. 

It is discouraging to realize that two-thirds of users may never open your app again after just one use. Those who do return are likely to be highly critical. Your aim should not just be to avoid falling into the category of quickly uninstalled apps. It would be best if you also strived to exceed user expectations. 

The Importance of Performance Testing

Testing is a vital phase in the development process of any mobile application before its market release. There are many types of application testing, including performance testing, integration testing, security testing, compatibility testing, and usability testing.

Today, I want to focus on performance testing. Performance testing is often overlooked, with a focus on features over system speed and efficiency, especially in API-driven architectures. Agile teams usually delay it, waiting for feature stability, and separating it from main development workflows. However, integrating performance testing early, alongside new code development, provides instant feedback, allowing for immediate fixes and aligning with evolving software practices.

Performance and load testing are vital steps, ensuring a stable and robust application that meets user expectations. Performance testing checks how the system behaves under various loads, focusing on indicators such as speed, reliability, and system availability. It identifies potential bottlenecks and weaknesses, which is essential for refining the app. This involves analyzing: 

• Resource usage levels under varying loads. 
• Errors that occur during the application's operation. 
• The maximum number of users the application can support before it becomes unstable.
• The performance of the subsystem responsible for managing load distribution.
• Potential weaknesses in the software's architecture.

Investing in thorough testing might seem costly, but it prevents the need for time-consuming and expensive fixes or modifications late in the development process. By ensuring your product is tested properly from the start in the secure SDLC, you save time and money in the long term and also accelerate its entry into the market. Adopting automated performance testing can also further reduce the cost of developing mobile applications. 

Core App Performance Testing Areas

For any mobile application, performance testing should be conducted across three critical categories: device, server/API, and network. 

1. Device testing is all about making sure the app works smoothly on different devices, paying close attention to startup time, how much memory it uses, and how much battery it drains.
2. Server/API testing emphasizes efficient data management and smooth interactions with the server, including API responsiveness and data exchange. 
3. Network performance tests assess the app's behavior across different network types, measuring speed, any packet losses, or connectivity issues.

Types of Performance Testing

Performance testing encompasses several types, each targeting different aspects of application performance:

Load Testing

This evaluates an application's performance under expected user loads to identify and address performance bottlenecks.

Endurance Testing

By applying a consistent load over an extended period, this test checks for issues that could slow down the application over time, ensuring the application's long-term performance stability.

Stress Testing

This tests an application under extreme conditions to determine its breaking point and how it handles massive traffic and data processing, aiming to identify at what load the application fails.

Scalability Testing

This determines the application's ability to scale up in response to increased user demand, ensuring it can grow to accommodate more users smoothly.

Volume Testing

This assesses how the application copes with a large volume of data in the database, ensuring performance is not compromised by data size.

Spike Testing

This looks at the application's response to sudden spikes in traffic, which is crucial for understanding how unexpected surges in usage are handled.

While it may be tempting to use as many types of performance testing as possible, the goal should be to select and prioritize performance tests based on the application's specific needs, usage scenarios, and the resources available for testing. 

Important Considerations When Doing Performance Tests

Testing mobile apps presents more challenges and can be more labor-intensive than testing PC software due to several important factors. The vast number and variety of mobile devices, the increasing mobility of users, and the unique features specific to each device make comprehensive testing a complex task. This diversity necessitates developers to test on as wide a range of hardware as possible, which can be time-consuming and resource-intensive.

There are various strategies for conducting mobile app testing, including lab testing, guerrilla testing, and unmoderated remote testing. While performance testing often relies on emulators for initial assessments, this method does not guarantee complete test coverage, for example, in cases like voice and gesture interface testing. Testing on real devices and with real users is more accurate.

You can find many services and companies that provide access to a vast array of real devices for testing purposes. This allows developers to select and test on devices that are most relevant to their target audience's preferences and the specific requirements of their clients.

Remember to always prioritize the user experience in performance testing. Beyond traditional performance metrics, focus on factors such as app startup time, responsiveness to user inputs, and smoothness of animations and transitions.

Do not forget to test your app under various network conditions, including different speeds (Wi-Fi, 3G, 4G, 5G) and qualities (high latency, low bandwidth), to ensure it performs well for all users. Consider geographic variations too.

Regularly review and adhere to the performance guidelines and best practices provided by Android, iOS, and other platforms, including those for application deployment, to ensure compliance and optimization.

After launching your app, continue monitoring its performance in the live environment. Real user monitoring (RUM) tools can help track actual user experiences and highlight issues that may not have been evident during testing.

Please note third-party services (like analytics, ad platforms, or payment gateways) may change rules and affect app performance. Regularly monitor their performance over time.

In addition, security is a major concern in mobile app testing. Malicious actors can exploit vulnerabilities in mobile devices, networks, and applications to gain unauthorized access to data or compromise user privacy.

For testing the mobile app itself, organizations should adhere to DevSecOps best practices and employ security processes like OWASP Mobile Security Testing. To ensure backend security, they have to rely on solutions like Dynamic Application Security Testing (DAST) or External Attack Surface Management (EASM) to discover, prioritize, and remediate vulnerabilities.

Improving Mobile Application Performance

Here are the top 15 tips for improving mobile application performance:

1. Keep the application's file size small. Users are reluctant to install apps that take up a lot of space. The smaller your app's footprint, the better it is.
2. Implement lazy loading for content and images, ensuring that items are only loaded when needed.
3. Optimize app images by using scalable vector graphics, implementing caching for faster loads, and simplifying color palettes for efficiency.
4. Minimize and optimize the use of animations. Although animations can enhance the user experience, they can also impact performance. Optimize animations by choosing lightweight formats and timing them carefully to avoid unnecessary consumption of resources.
5. Implement efficient data fetching strategies. Use techniques like pagination, infinite scrolling, or data prefetching to manage data loading efficiently.
6. Improve your application's memory efficiency by using memory-conscious coding practices and minimizing reliance on external libraries.
7. Minimize duplicate network requests, as they can degrade the app's performance.
8. Compress data for network transmission to reduce the amount of data sent over the network.
9. Use efficient queries and indexes in your database. Additionally, consider caching results of frequently accessed data to reduce database load.
10. Perform intensive tasks in the background using multi-threading or asynchronous programming. This prevents the UI thread from being blocked, ensuring the app remains responsive to user interactions.
11. Use the latest programming frameworks. They are designed with performance and efficiency in mind. Migrate to these technologies where possible to take advantage of their optimizations.
12. Optimize your app's energy usage by minimizing wake locks and using battery-efficient location services. 
13. Implement efficient error handling. It ensures that your app can recover from unexpected conditions without crashing.
14. Regularly profile your app's performance to identify and optimize slow or inefficient code paths. Android Studio and Apple Xcode can help identify performance bottlenecks.
15. Implement feature flags to toggle functionality. This allows for easier rollback of features that may introduce performance issues and enables A/B testing of performance optimizations.

Endnote

Testing, particularly performance testing, is crucial for app development, ensuring apps are robust, fast, and user-friendly. Covering various aspects like device compatibility, server/API performance, and network behavior, performance testing identifies potential bottlenecks and guides improvements. Automated performance testing strategies can save time and costs, enhancing market readiness and user retention.