How to identify web application performance issues and eliminate them rapidly

identify web application performance

How to identify
web application
issues and
eliminate them

Unlocking the secrets to a high-performing web application.

Web applications are a double-edged sword for a company’s reputation. Well-designed, efficient apps can turn users into brand advocates, encouraging them to leave glowing reviews and spread the word. Conversely, poorly performing apps can quickly lead to a barrage of negative feedback, which often gains more visibility on platforms like Twitter that are quick to amplify public discontent.

Therefore, investing in a high-quality web application is not just a technical requirement but a critical business strategy. Companies must allocate significant resources and time to anticipate and address any issues that could hinder their software’s performance.

This article will discuss a few ways companies can ensure their web apps aren’t driving people away.

Testing web app’s performance in the lab vs. the real world

What’s important to understand from the offset is that there is a tremendous difference between measuring web application performance in the lab and testing it in the “real world.” Web development tools such as DevTools, Lighthouse, and Webpagetest are essential to track performance testing and calibrate development efforts as the project progresses. They give a sense of how certain modifications affect apps, help catch regressions before they damage live production sites, and provide clear breakdowns so that development teams can get to the bottom of every issue and patch it.

What they can’t do, however, is recreate accurately the real-world environment, which is always messy and disorganized; there needs to be a tool capable of simulating the abundance of random network configurations and cache conditions that swarm the web.

the user-perceived performance. Define and implement Real User Measurements (RUM) and only track what you assume is essential to your clients and shapes their perception of the app. Ask yourself these questions:

When the app is loading, is there a proper indication that the server has responded and the navigation has started? What elements tell our users that the app is working?

Is there sufficient content rendered in the application components at the very beginning, and how soon can a user interact with the app in a meaningful way? Is there something blocking the interaction, and if so, why is that?

Is the experience free of jank and lags? Can we be optimistic that a user will likely enjoy the app and find it captivating?

The actual web app performance problems companies find hard to tackle

Web application performance is a complex landscape filled with challenges that companies often struggle to navigate. From server response times to memory leaks, these issues can significantly impact user experience and, by extension, your business. Let’s delve into some of the most common performance problems and how to tackle them.

1. Server response time is too long

Optimize web pages all you want, but if the server’s sluggish, your next web page or app will unfold slowly and annoy the user. The delays in the content rendering can be caused by several factors, including:

  • Sudden traffic influx
  • High usage of resources per page load
  • Outdated server software; poor configurations
  • Insufficient quality of hosting environment

According to Google, servers with slow response times should be at most 200ms.

What can be done about this?

We suggest identifying how many resources your app consumes for each page load as a starting point for slow performance. Then, if needed, proceed to optimize resources:

Gather all external CSS files into one file so that each web app page calls fewer resources. Locate external javascript files in the HTML or compile them in a single external JS file to keep performance data and reduce wasteful calls. Defer images so your app doesn’t download every image before displaying the initial content.

The next step to improvement is moving from a single server to a more advanced web host. You don’t want to stretch resources you already have scarce, so switch to a dedicated server if your web app is hosted on a shared account.

2. Memory leaks

The term “memory leak” describes a wide range of communication errors in computer science but, in its most common interpretation, refers to a situation when a bug in the code is causing the app to use progressively more memory over time. In other words, an object in a system eats the resources it isn’t supposed to, to the point where the entire app crashes, suffers slowdowns and high network latency, and performs poorly overall.

Even when garbage-collected programming languages such as JavaScript are used, which dramatically ease memory management, the leaks can still occur due to unwanted references; these issues can also go unnoticed for a long time, as detecting them is pretty tricky.

We won’t be delving deeply into the technical subject of app resource leakage, but in layperson’s terms, the explanation of the phenomena would go something like this. An appropriate amount of memory is assigned whenever a new object is created within an app’s code. Once active, each of these processes is monitored by garbage collectors (if we’re still talking about languages like JavaScript) that scan through object graphs from time to time to see which objects are still valid. When they find processes not referenced by any other processes (or those that only have circular references), they pull the memory out so there’s no waste.

A leak happens when some object that your app no longer needs continues to consume resources once assigned to it. For some reason, it doesn’t give back the memory that, by now, should be reclaimed for a pool of free memory or the operating system.

Memory leaks could be a sign of harmful code. So, to prevent them and avoid jeopardizing your web application performance, it’s best to hire developers who have written similar apps before and clearly understand the importance of proper memory usage.

Preventive practices include enforcing regular resource usage out of memory management tools such as Google Chrome’s Heap Management and having your development team create concrete expectations when specific resources in the object graph must be freed. Make sure they track memory distribution religiously and investigate carefully each unexpected result.

If object cleanups are planned, there won’t be a need to insert cleanup stages into applications later.

3. Database deadlocks

A web app’s performance can suffer significantly due to database deadlocks. These arise when two threads of execution are trying to access resources locked by each other.

For example, session A within a database is waiting to access some recourse that session B currently holds. At the same time, session B is also “hanging”; it’s expecting to reach the resource session A owns. The threads are thus both in a wait state, and there’s a cyclic dependency between them that allows neither to proceed.

Deadlocks are extremely dangerous as they can:

  • Undermine a poor user experience. A client might be shown white pages while the browser continues spinning frantically and, eventually, get the network time-out error on their screen. When they try to resubmit the form and refresh the page, they further escalate the issue.
  • Cause system degradation. When deadlocked, threads take longer to respond, and while they’re stalling, new requests are likely to pile up in the execution queue. Eventually, the tank will become full, and the system will deny all incoming requests.
  • Kill a significant business transaction. Whenever an SQL database spots a deadlock, it reacts by killing one of the deadlocked threads and reverting whatever transaction it was about to complete. By default, the system chooses as a deadlock victim a process that it assumes will take the least resources to roll back. Sometimes, it could abort a critical process, such as a high-scale business transaction.

When a deadlock alert pops up, your team must conduct a thorough investigation to fix performance issues and determine what has caused it. Tools like SQL monitor will help them inspect closely all the deadlock data and allow them to review the affected SQL server instance that shows Memory, CPU, and Input/Output over a selected time frame.

After the queries are analyzed, it’s time to remedy the issue by query tuning, modifying existing indexes, adding new ones, or using some other standard deadlock mitigation measures.

To avoid deadlocks, try:

  • Normalizing database design
  • Blocking users’ input during interactions
  • Reducing lock time
  • Utilizing bound connections
  • Making transactions shorter time-wise

Addressing web application performance issues like slow server response times, memory leaks, and database deadlocks is crucial for maintaining a positive user experience and ensuring business success. Taking proactive steps and employing best practices can mitigate these challenges and keep your application running smoothly. Remember, a well-performing app is not just a technical achievement but a business asset.


Web application performance should always be viewed through the lens of user experience. Once your app is developed, rigorously test its performance in lab and real-world scenarios. Utilize analytics tools to gauge how the app’s performance impacts your business metrics. For instance, if you’re tracking e-commerce conversions, set up reports to explore their relationship with app performance. If a strong correlation exists, prioritizing performance optimization is not just beneficial—it’s essential for business success.

Want to learn more about how to create a flawless app for business? Contact our experts for a free consultation right now.

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