Performance Testing: Strategies for High-Performing Apps

5 min read Michael Carroll on Jul 10, 2023
Application Performance & Quality Testing: Strategies for Reliable & High-Performing Apps-Blog.jpg

Owning an application is like owning a pet. They have their nuances, and you need to take the time to understand how they'll react to certain situations. Thankfully, this is easier with applications. Numerous performance testing methods are available to help developers understand how apps behave under different working conditions.

Performance testing aims to provide early feedback on application performance so teams can address potential issues during application development—a preemptive approach results in a better user experience and fewer application failures. 

In this article, we'll discuss performance testing, understand its importance in the development process, and learn about the most popular performance testing methods.

The importance of app performance testing

Performance testing is the ongoing process of testers evaluating how a computer, network, application, or device responds to a specific workload. It checks the system’s speed, responsiveness, compatibility, and stability to assess how many users, transactions, and volume of data the application can handle. 

Performance testing tools and data help DevOps teams understand the system, identify and eliminate bottlenecks, and create a high-quality user experience that meets the prerequisite requirements defined in the service-level agreement (SLA). You are using the test results to prepare your application for any workload by implementing scalability measures and better resource management. 

This way, you create a dependable application that gives you a competitive edge.

Performance testing KPIs

A performance test measures the following key performance indicators (KPIs): 

  • Memory is the storage space available for an operating system or workload.

  • Network bandwidth is the rate of data transfer per second across a network.

  • Throughput defines the number of units of data a system can process over a specific time period.

  • Peak response time is the highest time frame the system takes to complete a request.

  • Average latency (wait time) is a measure of the time it takes to receive the first byte after sending a request.

  • Error rate is the percentage of requests that result in an error.

  • Average load time is the average time it takes to deliver every request.

KPIs aren't limited to just these. A good performance test is designed based on the application’s requirements, so KPIs can vary from test to test. 

Useful application performance testing methods

Application performance testing addresses specific real-world working conditions. Depending on your needs, you can choose from a combination of the following testing processes:

Load testing

Load testing shows developers how a system behaves under a specific load value by simulating the expected number of real-time concurrent users and transactions during a fixed time period. It's best for calculating response times, latency, and bottlenecks before going live. 

Stress testing environment

Stress testing checks how a system functions outside normal working parameters, i.e., more users, transactions, and volume of data than the system can handle. Stress testing is done to review how a system responds when it fails and how it recovers. 

There are two types of stress testing:

  • A soak test plan increases the number of users over the expected limit over time to test the system’s long-term stability. It helps test memory usage, check for failures or performance issues, and analyze throughput and latency after sustained periods of use.

  • Spike testing tests the system’s performance during a sudden increase in the number of users. It’s usually conducted right before an event or update that will result in unusually high traffic.

Scalability testing

This testing approach simulates different workloads to measure up to which point the application can scale to handle spikes in traffic. The tests will measure KPIs (like real user/real device response times, screen transitions, throughput, network usage, memory usage, etc.) under each scenario. 

Preparation is key for a scalability test. You may have to take different approaches when testing each application to gather accurate data.

Performance monitoring 

Effective web and mobile app performance testing helps you connect an app's performance to its business outcomes. Performance monitoring is a collection of automation tools and processes designed to ensure the applications meet the performance, reliability, and user experience standards defined by the SLA. 

You can choose from different performance monitoring strategies depending on the requirement:

  • Front-end monitoring to see usability and how the app is performing from a user’s standpoint. 

  • Backend monitoring to monitor the services and dependencies used by the application. 

  • Infrastructure monitoring testing tools to ensure the infrastructure is well-configured and functional.

Keeping an eye on your app’s performance guarantees a seamless and transparent application delivery. It saves businesses money by avoiding unneeded application downtime and troubleshooting while earning your brand the trust of end users as a reliable application. 

PubNub Insights for performance monitoring 

If you're in the market for a performance monitoring tool, check out PubNub Insights, a user-friendly dashboard providing data-driven insights into user interactions and areas of improvement. A built-in feature of the PubNub platform, it leverages PubNub data to provide aggregated metrics and usable analytics that development teams, product managers, or business owners can use to create exceptional user experiences.

PubNub Insights has four distinct dashboards: 


This dashboard gives detailed analytics on unique channels in your publish/subscribe API. Technical and product teams can use this data to identify and address anomalies in your channel activities quickly. This way, you can maintain the highest performance and user satisfaction by avoiding overloads or failures.


The Users dashboard leverages advanced analytics to identify trends in user preferences and behaviors. The insights are derived from user location, app usage, and other relevant metrics. Businesses and product owners can use this information to proactively make informed decisions to meet audience demand and identify potential marketing or sales opportunities.


This dashboard shows you a detailed breakdown of data packages published in your channels. It presents usage rates across geographical regions and times to help you understand your biggest market and create strategies for that audience.


Snapshots provide a high-level summary of your channels, users, and messages dashboards. It makes analysis easier by consolidating all your data in one place. You can compare data across different regions and periods in the Snapshots dashboard. 

Each dashboard compiles the top user and usage data, which comes in handy when answering how, when, and why a feature is being used the most. This way, you can optimize and streamline your app’s features and allocate resources more efficiently. 

Understand your mobile application with performance monitoring 

With the rise of Agile app development, faster and more reliable testing has become even more integral to the development lifecycle and deployment processes. You can choose from different performance testing strategies depending on your application's functionalities. The data collected during testing can be used to mitigate any potential performance bottlenecks and provide the best user experience possible. 

However, you can’t monitor your app’s performance 24x7. You need a reliable performance monitoring tool that does the dirty work so you can focus on delivering a flawless application.

PubNub Insights compiles all the necessary information in four user-friendly dashboards to help you understand your users and applications. This enables you to decide how best to use your resources proactively. 

Get in touch with us to learn more about our offerings, or sign up for a free trial to explore how PubNub can bring your web applications and mobile apps to market faster.