Go back to all articles

SRE vs. Performance Testing: Exploring Synergies and Distinctions

Dec 8, 2023
6 min read

In our previous post, we explored the essence of Software Reliability Engineering (SRE) and skimmed the surface of its distinctions from performance testing. Now, let’s illuminate their common ground, delve into disparities, and decipher the skills that seamlessly transform a performance tester into an SRE.
It’s crucial to note that SRE encompasses diverse responsibilities, ranging from cloud platforms and databases to containerization and system architecture.

SRE and performance testing common ground

SRE and performance testing share a rich common ground, and it’s no coincidence that many skilled SRE professionals emerge from the realm of performance testing. Both fields recognize testing as a vital investment for engineers aiming to enhance product reliability, emphasizing that testing isn’t a one-time event but an ongoing process throughout the project lifecycle.

In addition, SREs and performance testers alike engage in continuous monitoring to track system behavior, conduct in-depth system analysis, and proactively search for potential performance problems and bottlenecks. This shared responsibility extends to exploring innovative solutions to address identified issues, highlighting the collaborative nature of ensuring system reliability and optimal performance.

Exploring the differences between SRE and performance testing

When considering the distinctions between SRE and performance testing, the primary difference lies in their work environments. SREs operate in live production settings, managing real user-generated loads. In contrast, performance testing occurs in isolated environments, using dedicated platforms like JMeter or LoadRunner to simulate loads.

However, this distinction is just the surface; the key divergence stems from the varied roles of SRE and performance engineers on a project. While SREs move beyond traditional performance testing approaches, their role extends broadly.

Improve Your Performance
Discover how our solutions and services can transform your project
Get a quote Learn more and get started today

Responsibilities of software reliability engineers

SREs skillfully apply classical software testing techniques at scale, covering the entire spectrum from development to troubleshooting. Their responsibilities encompass defining target metrics and establishing automation for both testing and incident response mechanisms, transcending the boundaries of conventional testing roles.

The responsibilities of an SRE are multifaceted. In essence, an SRE shoulders the responsibility for the performance, stability, and availability of the system, collectively defining its reliability. Let’s delve into each of these components.


Software reliability engineers meticulously evaluate the performance of the entire infrastructure, including components like balancers, databases, and buses. This encompasses provisioning the infrastructure to ensure suitability without limiting future deployment. Their in-depth analysis aims not only to identify current performance bottlenecks, but also to proactively prevent issues that might arise with increased load.

Capacity planning

In addition, SREs are tasked with capacity planning. Differing from the conventional role of performance engineers, they go beyond identifying and localizing bottlenecks; they are proactive in preventing such issues by making the increase in load on the infrastructure predictable.

Consider a scenario where your system is deployed on hardware in a Kubernetes environment. Here, an engineer can implement a set of triggers that activate when the load on the cluster reaches, for example, 80%, providing foresight to procure additional hardware in advance. This predictive approach ensures smooth scalability and optimal performance.


System stability denotes its capability to operate without any crashes for an extended duration. Stability practices are intricately tied to the expectations we set. These practices can be categorized into two groups: the formulation of requirements, such as those for deployment and runtime, and proficient incident management. This ensures a swift and precise identification of unmet requirements and the reasons behind them. Effectively managing incidents contributes to sustained system stability by promptly addressing any deviations from SLA.


Availability refers to the time when a user can access and receive the services provided by your application. In simpler terms, it signifies the ability to navigate through the predefined business processes. Any failure in the system or its components results in tangible losses for the company. Thus, maintaining high availability is crucial to ensure uninterrupted access to services, minimizing disruptions, and mitigating potential financial losses.

Error budget

Availability is commonly measured by calculating the time per month without any delays or failures across the entire customer journey. To monitor this metric, an error budget is often employed. These parameters are defined by a company’s Service Level Objective (SLO). For instance, if the SLO is set at 99.9%, indicating 0.1% allowable errors, and the service is expected to be available for 168 hours weekly, with downtime not exceeding 1.68 hours.

Depending on your business, stability may need separate assessment, with tailored requirements for distinct user groups. The SRE vigilantly monitors the error budget, triggering an investigation when it starts depleting, ensuring prompt resolution, and upholding system reliability.


Finally, as for reliability, software reliability engineers take on the responsibility of defining requirements for fault tolerance. This involves implementing various patterns like Retryier, Burst/Rate Limiter, Circuit breaker, Balancer, and Graceful degradation/fallback. To evaluate the collective effectiveness of these patterns and ensure the desired level of fault tolerance, SREs conduct specialized tests, such as Chaos engineering. These tests provide a comprehensive understanding of how these patterns function together and their capacity to handle unexpected failures or disruptions.

Production testing

Unlike the typical approach of performance testers, SREs actively employ tests in production. Engaging in the live environment offers a distinct opportunity to closely collaborate with product teams, enhancing comprehension of system behavior, and enabling real-time troubleshooting.

Automation in SRE

SREs leverage automation to streamline tasks, respond rapidly to incidents, and maintain system health at scale. Automated monitoring keeps a constant watch, catching issues early. Scripted deployments and configuration tools maintain consistency and minimize the chance of human errors. By automating capacity planning, incident response, and change management, engineers enhance the reliability and stability of systems, contributing to a seamless and efficient operational environment.

Implementing automation in SRE usually includes crafting scripts, employing configuration management tools like Datadog, Prometheus, or Ansible, and building workflows with tools such as Jenkins. For instance, a scripted deployment process might involve automatically updating software across servers, while configuration management tools help maintain consistent server configurations. Workflow automation tools assist in orchestrating tasks, ensuring efficient execution of routine processes like scaling or incident responses.

Want to Learn More About Our Performance Testing Services?

Find out what’s included and how to start working with us

Performance testing services


As you can see, SREs blend traditional testing methodologies with scalable approaches, emphasizing automation to ensure sustained performance, stability, and availability. This underlines the broader responsibilities of an SRE, marking a dynamic progression in the domain of system reliability.

Table of contents
Let us know about your needs
We can provide multiple performance testing services and a lot more than that if the situation needs a far more complex approach.
Get a quote You’ll hear back from our tech account manager in one day if not sooner

Related insights in blog articles

Explore what we’ve learned from these experiences
8 min read

Why Load Testing Is Essential for Ecommerce Businesses

why load testing is essential for ecommerce businesses preview
May 17, 2024

The success of 26 million online retailers depends on the page load time. It significantly impacts the profitability of online services and sales, as customers don’t want to wait over three seconds to make a purchase. To ensure the desired speed, load testing is widely applied. Common Ecommerce Problems That Can Be Solved with Load […]

8 min read

Everything You Should Know about Performance Testing of Microservices

everything you should know about testing microservices preview
May 2, 2024

About 85% of enterprise businesses use microservices. In this article, we will cover the primary specifics of microservices, explain why they need performance testing, and highlight how to make this process efficient. Microservices in a Few Words Microservices (or microservices architecture) refers to a methodology for developing and deploying applications. This approach separates an extensive […]

4 min read

PFLB is Now SOC2 Compliant

pflb is now soc2 compliant preview
Apr 24, 2024

The PFLB team is happy to share the good news. We have passed the SOC 2 compliance accreditation. It means we can assure our clients that our cooperation will be entirely secure. What Is SOC? Introduced by the American Institute of CPAs (AICPA), SOC, or Service Organization Control, is a cybersecurity series of reports made […]

11 min read

How Do Businesses Benefit from Frontend Performance Testing?

how do businesses benefit from frontend performance testing preview
Apr 15, 2024

Crucial bottlenecks are usually backend-related. That’s  why backend performance testing is generally regarded as a must. However, only 1% of companies perform frontend performance testing. They don’t consider that to achieve the best business results, one should combine the two types.  Let’s prove it. We will define their differences, emphasize the importance of conducting backend […]

  • Be the first one to know

    We’ll send you a monthly e-mail with all the useful insights that we will have found and analyzed