Importance of Load Testing for Real-World Applications

Heavy Weights

In the past decade, the digital footprint of Indian citizens across the world wide web has increased manifold, with people adopting smartphones in huge numbers. 

App-based solutions and services are now the hype. Want a ride, call Uber. Want some food delivered, just Swiggy it. Need some groceries, place an order on Bigbasket, and within 24 hours, you will have it at your doorstep. 

Amidst the COVID-19 pandemic, app-based services have played a significant role in connecting the nation and supplementing the major necessities of the supply chain. This was only possible because applications could scale based on the rapidly increasing demand for digital services. Applications for e-commerce, web conferences, direct-to-home delivery of consumer goods/ vital medicines, gaming applications…etc, are just some of the various segments which have seen a boom since the lockdown began in March. 

As a developer, your primary function is to enhance the customer experience. This does not only mean onboarding a prospect but ensuring that your application is their number one choice every time they are looking to avail of some service. 

One of the most important ways you can achieve it is through performance testing, more specifically, load testing.

So, what is load testing?

Load testing is part of a much larger albeit general process called performance testing. 

TechTarget defines load testing as ” the process of subjecting a computer, peripheral, server, network, or application to a work level approaching the limits of its specifications.” 

In simple terms, the idea behind load testing can be said to be about simulating real-world environments and understanding how the application behaves to those test parameters. This can be done for the entire end-to-end process, which helps developers understand what bottlenecks the application comes across and how those can be solved. Most applications experience surges in traffic at various points of the day, month, or year. 

In this article, we will try to understand why load testing is an essential part of software life cycle development.

How does load testing work?

Individual components of the entire system are subjected to a check. The KPIs measured could be the speed, capacity of the system, the transaction response time, and many more things. 

When nearing its peak, the response time may extend, and the functionality may blur or even become unstable. Developers use these cues to identify which parts of the application may experience lags and bottlenecks and solve those accordingly.

Tools for load testing?

Various tools in the market allow you to perform this test on your application based on your business needs. A few of these tools are, WebLOAD, NeoLoad, Locust, Apache JMeter, Loadrunner, and LoadView. Each tool has its own set of rules and parameters, so you can choose the best based on the functionality of your application. You can find more tools over the internet.

What are the different types of load testing and tool categorizations?

There are a few different types of load testing methods that are typically used in the industry.

Manual Load testing

This type of load testing can be performed manually or with automation. Since everything is done manually in this category, loads cannot be the most excessive. It may not be physically feasible to apply large amounts of the load over the application since you may not have the required workforce. Hence, this type of testing can be costly.

Custom Load Testing Tools

You may sometimes be in a situation where you need a testing tool or mode for complex scenarios that may entail large amounts of data. In such a situation, you may need a custom lead testing tool suited to your requirements. Since this is made in-house, it may come at a price and increase in-house investment. But the pros mostly outweigh the cons as you get a specialized tool for all your needs.

Open Source Load Testing Tools

As discussed above, many tools already in the market allow you to choose from standard testing parameters. Since they are open source and free to use, they are designed to require minimal customization. They are primarily employed when the users want to do simple scale or small tests. You can choose which tools may be the best fit for your application.

Enterprise-level and corporate load-testing tools

These tools are primarily designed for large-scale, precision, in-depth testing capability. Their primary ability is to subject vast amounts of traffic and measure application performance under those conditions. 

Load testing Vs Performance testing

The basic distinguishing difference between performance testing and load testing is that, with performance testing, you subject the entire system to specific load conditions and observe its behaviour, whereas, with load testing, you subject the system to intense amounts of demand and measure how it responds under both normal and peak loads.

Best way to perform load testing

Identify the end goals of the application.

Understanding how the business may grow and how/ where it can draw volume from the most will help you set realistic expectations and parameters for the test.

Define KPIs

Maximum load, response time, business performance metrics, resource utilization, etc., are some of the many KPIs that can be used to track application behaviour.

Find a suitable tool

Various tools, as discussed earlier, may suit your requirements. 

Create scenarios with specific parameters

Ensure both low and high-end scenarios are explored thoroughly. Ensure that a bottleneck analysis is run multiple iterations to completely solve it from happening.

Understand the built environment

Different environments of deployment will give you different results. Try and create scenarios that may be closest to the actual deployment scenario.

Perform multiple iterations

As a developer, you should run the tests over multiple iterations, ensuring that you keep tweaking the test parameters each time. The idea behind this is to understand at what user demand will the application start to cave.

Always keep the end-user in mind.

In India, the application development process is highly customer-centric, meaning that there may be massive strata that might not be as tech-savvy as you. The tech needs to be user-friendly, fast, and simple to use. Load testing can help you deliver on these parameters for faster adoption rates amongst Indian users.

Benefits of Load Testing

There are various reasons why load testing is a must to ensure seamless performance over different loads. A few of these have been mentioned below:

Effortless Scalability

It is essential to deliver functionality with an ever-increasing growth rate for growing businesses. Hence, load testing can be used to identify the operational capacity of the application and help us understand what type of infrastructure will best solve the problem in the long run. 

24X7 Availability

With scalability come users from around the globe who will be using your application. Your services should be available to them without any delay. This is an essential part of customer experience, and hence load testing can help you understand how you can deliver the same. Application availability and unexpected user load are two parameters that you can gauge through load testing.

Debugging the application

When subjected to heavy user demand, the system may reveal bugs that may ruin the processing capabilities of the application. To deter such issues, developers must perform the debugging under various controlled load testing environments. 

Avoiding costs due to application crash

Load testing helps you cut down on costs related to the launch of the application. At the same time, it also enables you to reduce costs by identifying potential failure modes at the earliest stage possible. Post-launch, such a failure of the application can create exponential problems in terms of finances.

Improved customer satisfaction

As said earlier, developers must ensure that their applications can retain customers through the services. Suppose the user experience is seamless at the end of the day while scaling towards a more extensive user base. In that case, it creates more revisitors to the application and reduces the customer churn rate.

Identification of inefficient code

Load testing also helps a developer experiment with the application and how the overall function execution time can be brought down by using different pieces of code or the programming language of the code. With inefficient code, the application can be assumed to be punching above its weight and bound to failure. 


Load testing is critical to the software life cycle development or SLCD. Application development must include a robust strategy for testing and deployment. The insights that will be drawn from the test will only add more value to the application and enhance the customer experience.

The point of this article is to ensure that you make load testing a must while developing the next Zoom, Facebook, or the next Instagram. It will also allow developers to create contingencies and identify the various failure modes. It would be best if you started practising this as a habit for your next venture.

Leave a comment: