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YamShalBar
YamShalBar

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Lessons Learned: My Journey in Load Testing Concurrent Users

Hi, I’m Yam, CTO at RadView. Over the years, I’ve worked with teams across industries to tackle some of the most demanding load testing challenges. One of the most crucial aspects of performance testing—and often one of the most misunderstood—is testing for concurrent users.

This blog isn’t a technical walkthrough. Instead, I want to share a personal perspective: stories, lessons, and strategies I’ve found invaluable in helping organizations optimize their applications for real-world traffic conditions.

*The Human Element in Load Testing
*

Before we get into the technical details, let’s consider the “why” behind load testing for concurrent users. Think of your application’s users as people, not numbers. Each action—a click, a login, a purchase—represents someone’s time, expectations, and trust.

One of my first major load testing projects was for a ticketing platform preparing for a high-demand concert release. They were confident their system could handle the load until we ran the first test. Within minutes, their servers were overwhelmed. What we uncovered wasn’t just technical bottlenecks; it was a lack of understanding of user behavior during high-stress events.

*Three Real-World Lessons
*

  1. Load Testing Is a Team Sport

During a project with a healthcare company, we discovered that performance bottlenecks weren’t just about server capacity. Poorly optimized workflows and database queries were equally at fault. Collaboration between developers, testers, and product managers was the only way to identify and address these issues effectively.

  1. Start Small, Scale Smart

For an e-commerce client, we began testing with just a few workflows: browsing, adding items to a cart, and checking out. By starting small, we quickly identified where the system began to strain. Only then did we scale up to more complex scenarios, saving time and resources.

  1. Expect the Unexpected

When working with a government portal, our tests revealed an unexpected issue: user sessions weren’t terminating properly, leading to server overload. The fix required a combination of code changes and infrastructure updates—a reminder that even seemingly minor oversights can have significant impacts under load.

My Approach to Concurrent Load Testing

Understand Your Users:
Load testing should reflect real user behavior. For example, during a recent project for a streaming service, we didn’t just test login functionality. We simulated users switching devices, pausing, and resuming streams—actions that stressed the system in unexpected ways.

Focus on Critical Journeys:
Not all workflows are created equal. Identify the critical paths that drive business outcomes—whether it’s completing a purchase or accessing a key service—and prioritize them in your tests.

Use Tools Intelligently:
I’ve seen teams overcomplicate testing by using tools in ways they weren’t designed for. Tools like WebLOAD are purpose-built for simulating complex, real-world scenarios at scale. Focus on leveraging their strengths rather than trying to force them into every use case.

Iterate, Don’t Perfect:
Every load test is a step toward improvement. Don’t aim for perfection in a single test; instead, use each iteration to refine your approach and uncover new insights.

Final Thoughts

Concurrent user load testing is about more than preparing for peak traffic. It’s about understanding your system, your users, and your goals. It’s about finding opportunities to create exceptional experiences, even under the most challenging conditions.

For a more technical deep dive and additional examples, check out my latest article on the RadView blog: Read More Here.

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