Could RTE blind spots be compromising your web app's performance?

In today’s fast-paced digital world, delivering seamless and efficient web application performance is non-negotiable. But there’s a major area that is often overlooked in performance engineering: remote terminal emulation (RTE). For organizations relying on mainframes or other legacy, terminal-based systems, blind spots in performance testing can introduce vulnerabilities that compromise the front-end web processes that rely on them. Let’s unpack why RTE testing matters and how to ensure your systems are up to modern performance standards.

What is RTE, and why does it matter?

RTE protocols enable testers to interact with legacy mainframes, but they require specific handling during testing to accurately emulate the behavior of real users, and creating tests often requires complex scripting. While these systems might seem outdated, most large enterprises still rely on them, and they remain the backbone of IT operations in many industries like finance, retail, and logistics. Recent research indicates that 71% of Fortune 500 companies still rely on mainframes, which process 90% of global credit card transactions.

For decades, these systems have been robust and reliable. However, their integration with modern web apps introduces new challenges. Today, systems that once supported a small number of back-office users are now exposed to web-scale demands as APIs, and applications access mainframe data for real-time transactions, such as inventory updates or banking activities. These activities can put unprecedented load on your legacy systems that can compromise performance of the entire end-to-end process. If you’re not testing the entire process, you risk leaving a significant blind spot in your performance testing strategy.

The blind spots in RTE performance testing

1. Underestimating load impact

Many organizations assume mainframes can handle any load. Yet, as web and mobile apps channel thousands of concurrent users to the mainframe, the strain can reveal unanticipated bottlenecks. For example, grocery store inventory systems now support real-time updates for online shoppers — pressure these systems were never originally designed to handle.

2. Legacy complexity

Modern performance engineers often lack familiarity with the use of RTE protocols, leading to under-tested scenarios. Unlike web apps that can scale horizontally with additional servers, mainframe systems are vertically scaled and constrained by their core hardware. This can lead to an assumption that mainframe testing is not required. And even on teams that recognize its importance, it can be difficult to carry out. That’s because traditional approaches demand good scripting skills and knowledge of correlation and error handling in scripts.

3. Integration challenges

New applications often integrate with legacy systems through APIs. These interfaces can magnify performance bottlenecks, and those bottlenecks can wreak havoc on your production systems if they are excluded from end-to-end performance testing. For instance, slow response times in mainframe queries can cascade downstream, degrading the performance and reliability of your web app and compromising the user experience.

Tricentis NeoLoad: Bridging legacy and modern testing needs

In the push toward digital transformation, don’t let legacy systems become a liability. If the web applications you’re testing rely on integrations with mainframes, overlooking their performance risks creates blind spots that can surface in production. By leveraging NeoLoad’s simplified RTE testing capabilities, organizations can bridge the gap between legacy reliability and modern performance expectations — ensuring seamless, high-quality user experiences across platforms. With NeoLoad, you can design an RTE test in just a few keystrokes, without the complex scripting that traditional approaches require.

Tricentis NeoLoad’s built-in RTE protocol support makes it easier than ever to test terminal-based systems alongside modern applications and assess holistic performance as part of a unified workstream. Its low-code scripting and easy-to-use interface empower teams to simulate realistic mainframe workloads without requiring deep technical expertise, so you can carry out end-to-end performance testing fast. Watch this webinar to learn more about NeoLoad’s RTE capabilities.