Did you know that your mobile app would be abandoned by the user if it failed to load 3 seconds after the launch? In its turn, it results in lower conversions and a decrease in ROI. In the modern business environment, high app performance is one of the things you need to strive for if you want to make a profit through the mobile app.

Taking the importance of the topic of application performance, we have decided to create a list of issues that slow down the app as well as practices and methods that we use to improve app performance on our commercial projects. This article also features a real-life case of a code audit that we have recently run.

Why does your app need to perform exceptionally well?

Nowadays, so many digital resources are available to us that we have very high expectations for their performance. Just have a look at the following stats:

• Research made by Google shows that the visitor will leave the page of the mobile resource, be it a mobile website or an app if it doesn't load within 3 seconds.
• The report called “The need for mobile speed” compared apps that load in 5 and 19 seconds. It turned out that apps that load within 5 seconds are more successful in several parameters: 25% higher ad viewability and 70% longer average sessions.
• The same report says that 46% of people say that waiting for pages to load is what they dislike the most when browsing the web on mobile devices.

With these stats in mind, we can conclude that many resources need to be invested in improving app performance, as it can result in a lower bounce rate, higher retention, and user satisfaction as well as conversions in your digital resource.

What are the criteria for good application performance?

The term good app performance might be bewildering. That's why we'd like to explain what good performance is for us. Here are a few parameters:

• Stability and reliability — a well-performing app should run smoothly, without bugs and frequent crashes.
• Quick loading — the stats above prove that loading speed is a key performance metric.
• Efficient resource usage — a well-performing app should use system resources such as CPU, memory, and battery efficiently, without draining the device's resources excessively.
• Smooth integration — the good-performing apps are smoothly integrated with third-party services used during the app development.
• Consistent mobile app performance — the app should perform equally well on all the devices and operating systems it was developed for.
• Security — good app performance includes maintaining robust security measures to protect user data and prevent security breaches, without compromising the app's speed or responsiveness.
• Responsive user interface — a good app responds promptly to user interactions and provides users with hints explaining what is happening within the app.

What factors can spoil app performance?

Several factors can slow down the performance of your app, affecting user experience and potentially leading to lower user engagement. Below we'd like to enumerate several basic factors that can worsen both web and mobile app performance.

Inefficient code

Inefficient code is characterized by a lack of proper documentation, making it challenging for developers to understand and maintain. It often includes overly long and complex functions that hinder readability, debugging, and extensibility. Additionally, the presence of repeated code and inadequate error handling mechanisms in inefficient code can lead to maintainability issues and application crashes, negatively impacting the user experience.

The optimization of the code can help to avoid this problem. If the code is inefficient, you'll need to work with experienced developers to refactor and optimize the codebase to improve it. This can involve removing redundant code, improving algorithms, and following coding best practices to enhance mobile app performance.

Large file sizes

During the development, the development team can either use heavy files or optimize them for quick loading. Large file sizes can slow down application performance by increasing loading times and consuming more device resources than necessary. To address this issue, developers can optimize images and videos, use efficient file formats, and implement lazy loading techniques to load content only when needed.

Lazy loading techniques are when the images are loaded on the page only when they are visible. This eases up the loading of different files. These techniques work as shown in the following picture.

Network issue

Network issues can include poor connectivity or server issues. They can cause problems with data retrieval and app functioning. Implementing data prefetching, offline capabilities, and handling network errors gracefully can improve app performance under such circumstances.

Background processes

Background processes are the tasks and operations that happen in parallel with the execution of the app's main functions. These processes can include updating content, syncing data, handling notifications, or performing system maintenance tasks. The background processes compete with the main functions of the device's resources, which can impact the app's performance and responsiveness.

Developers can address this issue by identifying critical tasks that need immediate attention, optimizing background operations to consume fewer resources, and implementing effective task scheduling to ensure that background processes do not hinder the user experience or slow down the app.

Too many requests

Requests are the actions that an app performs to retrieve data or send it to the server. When an app sends and receives too many requests from the server simultaneously, it can overload the server's capacity, leading to delays in processing these requests and potential timeouts.

To counter this problem, developers can implement request batching, a feature that combines several requests into a single one reducing the server load. Additionally, utilizing data caching techniques can store frequently accessed data locally, minimizing the need for repeated requests to the server. By optimizing APIs and streamlining the request-response process, developers can reduce the number of requests sent to the server, improving app performance and ensuring smoother data retrieval processes.

Lack of caching

In the context of mobile app development, caching involves storing frequently accessed data locally, such as in memory (memory caching), on disk (disk caching), or in a network cache (network caching). When data is cached, the app can retrieve it swiftly without having to fetch it from the server each time, thereby reducing latency and improving performance.

By implementing caching mechanisms like memory caching, disk caching, and network caching, developers can optimize data retrieval processes, minimize the amount of data fetched from the server, and provide users with faster and more efficient app operations.

Issues with device compatibility

Although the app might be developed for several operating systems, the user experience might not work exceptionally well and consistently in all of them. To avoid bugs and inconsistencies in all app versions, they need to be tested on various devices before the release.

Except for these issues, many other tech problems can evoke crashes and slowdowns. Here's a short list of the additional performance issues connected to the tech part:

• Complicated hierarchy of the navigation
• A large number of elements and components with complex structures on a page or screen
• Unoptimized images
• Heavy computations in the main thread
• Poor implementation of animations
• Use of unoptimized third-party libraries
• Large number of simultaneous requests, as well as if the server responses are unreasonably large, with excessive or complex data structures
• Use of inappropriate components for rendering
• Insufficient code separation, no lazy techniques implementation
• Use of inefficient CSS selectors

Poor UI/UX design can also become a reason for app performance feeling slow. Here's the list of issues:

• Overloaded UI
• Lack of loading indicators, failure to use skeletons when loading
• Instant appearance of large data volumes
• Unoptimized loading sequence
• Lack of smooth animations
• No immediate response to user actions

As you can see, there are a lot of issues that need to be taken into consideration when it comes to creating high-quality application performance. Unfortunately, none of them can be fixed without the help of a team of experienced developers and UI/UX designers. That's why if you want to improve app performance you will need to either ask outsourced developers for help or hire in-house ones. Both of them can help you counter tech issues and maintain good mobile app performance.

How does the Ronas IT team organize project work to ensure that applications run smoothly without performance issues?

Our team has already developed many apps for various mobile devices and tablets, as well as web apps. During this time, we have found the workflow that helps eliminate performance issues at each stage of the software development process. Here is a list of methods and practices that help us with that:

UI/UX design optimized for development

The creation of the interface starts with the work on the UI/UX design mockup. During this stage, it's important not only to build up a beautiful and eye-catching UI but also to create mockups that would be easy to implement in code.

In our team, designers and developers work closely together to create UI/UX designs. They run project meetings where they discuss small issues that can affect the development quality and speed. As a result, after the developers get the mockup fully ready for development and optimized to the requirements of the operating system.

An easy-to-implement design results in quicker development time and improved app performance, as it fully complies with the tech requirements of iOS or Android systems.

Proven practices

We have already worked on many projects for our customers, and over time, we have elaborated our own standards and approach to development.

Our team follows a proven architecture and established methodologies for implementing various features. We run code reviews, organize our teamwork effectively, and focus on quality throughout the development process. Standardized release procedures and thorough checklists are implemented before each release to ensure consistency and reliability in the final product.

Code review

Each task on the project is exposed to code review. Code review is a process in software development where developers systematically inspect, evaluate, and provide feedback on code changes made by their peers. There are two ways we benefit from this procedure:

First of all, it helps us to find bugs in the code before the product release. The readability of the code also improves as the code is reviewed by 2 or more team members. The completed code review means that the code is understandable to several members of the team, which makes it easier to maintain.

Secondly, our code reviews are run not only by a team lead but by the entire project team. This helps all the team members to understand the overall goal of our work better. More than that it helps to share good code practices and improve the coding skills of the entire team.

Tools for bug catching and speed measuring

Manual error tracking and bug fixing are effective and help to troubleshoot many of the performance issues. However, we also use automatic tools to improve app performance. For instance, we often implement Sentry and Datadog to track errors.

Sentry and Datadog are essential tools for application performance monitoring. Sentry helps identify and track errors that occur within the app, providing detailed information to developers so they can quickly troubleshoot and fix issues that may slow down the app.

On the other hand, Datadog allows developers to monitor various aspects of the app's performance, such as server metrics, response times, and resource usage. By utilizing both Sentry and Datadog, developers can gain valuable insights into the app's behavior, address performance bottlenecks promptly, and ensure that the app runs smoothly and efficiently.

Except for error-tracking we also use Datadog to measure the load speed of the applications. We also use PageSpeed Insights and Sentry Performance Monitoring for these purposes.

Performance testing

Testing is an essential part of our development process. During testing, various procedures are followed to assess functionality, user interface, security, and application performance. This includes checking for bugs, errors, and inefficiencies in the code, as well as validating that the app functions as intended across different devices and scenarios.

In our team, the testing is run by the team of developers as well as by the team lead and managers before it is presented to the customer.

Research and development

We constantly test and use new technologies to find the most up-to-date and efficient solutions for our apps. The usage of such technologies helps us to keep up with market trends and improve app performance. We even run our Ronas IT Radar where we collect information about all the technologies and frameworks we've tested, and document the results of the experiments. Some of the tested technologies stay with us, while some are abandoned.

UI/UX design tricks that make your app's load time feel faster

No matter how well the app's code is written and how good its UI/UX design is, users will experience some wait time anyway. Luckily, some tricks in UI/UX design can make the app feel faster. Our key advice here is to never let the user wait without feedback. There are several ways we can give it to users:

Add loading indicator

When providing users with feedback about loading, it's better to provide them with dynamic indicators, not static ones like signs “Loading” or “Please, wait…”. Instead, implement a loading spinner for fast actions taking 2–10 seconds or a percent-done animation for actions that take 10 seconds or more.

You can also provide users with a progress bar, so they can know exactly when the action will take place. To make the progress bar feel faster, don't allow it to freeze, as this will frustrate the user.

Implement skeleton screens

Another thing that can make your app feel faster is screen skeletons. They are the blank versions of the screens in which the data is gradually loaded. Rather than displaying a generic widget, skeleton screens create a sense of anticipation for forthcoming content, directing the user's attention towards progress rather than idle wait times. These techniques can be further optimized for mobile applications by storing the skeleton template alongside the app's data, enabling swift loading.

Create a visual distraction

You can make waiting a more pleasant process by adding a funny animation or a picture to the loading screen. This will distract users and make them pay less attention to slow loading time.

Gradual image loading

A progressive image-loading effect in mobile and web apps can be achieved by implementing a blurring effect. A prime illustration of this technique can be observed in Medium's approach, where post images, including the cover image and those within the content, are initially displayed in a blurred state until the image loading process is complete. It's the lazy loading technique that we have already discussed.

Ronas IT case of mobile app performance improvement

Our team specializes in creating applications from scratch, which means we can create a mockup for the app and then code a fully functioning interface. We also work with both web development and mobile app development projects. Through working on such projects, we have gained vast experience in analytics, UI/UX design, and development that we now use to consult customers. For instance, we can estimate your project, check the estimate provided by other companies, run independent code reviews and provide some advice about the improvement of your app, create redesigns, and run code refactoring.

Task. This was exactly what happened in the story below. One of our customers approached us to get a code audit of an already existing app. Our task was to check code, find bugs and errors, and give our recommendations on how to improve app performance.

Tools. During the code audit, we both worked manually and used automatic tools to estimate the quality of the app's backend and mobile parts. In the process, we checked the code with the help of SonarQube and IntelliJ IDEA. They are used to find errors and inefficiencies, bugs, and vulnerabilities that spoil mobile app performance. Moreover, the code was studied by our senior developer to find inefficiencies missed by the automatic tools and find potential areas of improvement.

Result. After running the code audit, we described all the issues that we found in detail and arranged them into a written PDF report.

It turned out that the code had too many lines and inefficiencies affecting the code readability and app security. Some of the code's functions were too long, which made the maintenance too complex.

After all the review was completed we offered technologies and practices that could be used to optimize the code and improve the overall experience. Unfortunately, our CTO and lead developers came to the conclusion that the app code needs to be refactored and run full performance optimization to keep up with up-to-date performance and speed requirements.

The customer was satisfied with our work, which is why they stayed with us to rewrite the app's code based on our offers.

Wrapping up

All in all, the app performance is one of the key things you need to prioritize since slow-performing apps will likely be abandoned by the users. Unfortunately, the app owners can't do anything with bad performance independently if they don't have tech experience. That's why the only thing that can be done in such a situation is to ask for the help of professional IT developers and designers, either in-house or outsourced. There are many professionals ready to offer their assistance. If you choose us amongst them, we'd gladly take on your project and work diligently to make it lightning fast.