Website Resilience Testing: Ensure Your Site's Performance

Website Resilience Testing: Ensure Your Site's Performance

Learn how to evaluate your website’s resilience with a website resilience test. Here are tips and tricks to improve your site’s performance and user experience.

BugHerd Dev


June 5, 2023

Website Resilience Testing: Ensure Your Site's Performance

In a dynamic tech world that faces frequent cybersecurity threats and uncertainties, website resilience testing is crucial for running a reliable website. It reduces downtime, prevents data losses, and lowers the impact of a server crash in order to prevent interruptions to the user experience.

Depending on the industry and customer base, a website outage can cost companies anywhere from $1,000 to $2 million per incident. In a worst case scenario, this temporary loss could lead customers to permanently lose trust and turn their attention to competitors.

The best prevention measure against unexpected disasters? Website resilience testing.

Resilient websites can weather the storm of traffic surges, cyber-attacks, hardware failures, network outages, and countless more unplanned events that can harm your website’s functionality.

Read on to learn more about website resilience testing. We’ll teach you some of the key strategies and approaches for keeping your site in tip-top shape.


  1. What Is Website Resilience Testing?
  2. How to Perform a Website Resilience Test and Optimize Your Site’s Performance
  3. Examples of Resilience Testing at Established Brands
  4. Difference Between Reliability and Resilience Testing
  5. How Resilience Testing Can Help Your Business
  6. Performing Quality Assurance Testing With BugHerd

What Is Website Resilience Testing?

Website resilience testing, also known as website availability testing or performance testing, evaluates how well a website can perform in the face of real-life disruptions, failures, or other chaotic conditions.

Think of it like a business strategy stress test, but with technology as the focus.

Businesses can use resilience testing to identify security flaws and weaknesses throughout the infrastructure of their website.

Identifying these flaws and weaknesses before they become an issue allows businesses to make proactive security enhancements that improve their site’s resilience and ability to recover from unforeseen circumstances.

How to Perform a Website Resilience Test and Optimize Your Site’s Performance

When it comes to resilience testing, there are no shortcuts. It’s a necessary but time-intensive activity.

Thankfully, we have some tips for how to ease and streamline the process. Take the following steps to perform your first website resilience test.

Determine Testing Metrics

The first thing you need to do is define the scope of what, specifically, you need to test.

For example, have you noticed if your website is prone to slowdowns during periods of high or unusual traffic?

If you’re still not certain which resilience-related issues to test, speak with your development team. They will review your website’s recent performance stats and single out urgent issues that could put the website at risk.

Urgent resiliency issues could range from the site’s ability to recover from hardware failures to its defense against potential denial-of-service (DDoS) attacks.

Once you know the parameters of what you’ll need to test, you can move on to the next step.

Define the Performance Baseline and Test Scenarios

Look at the test metrics you’ve defined.

In order to test them, you need to establish a performance baseline for how much stress or load that each metric should be able to withstand.

The higher your performance baseline, the higher the standard your website must meet in order to consider it resilient.

Next, brainstorm your test scenarios — also known as failure scenarios.

Test scenarios are the specific conditions or challenges to which you’ll subject your website in order to test its resilience.

Depending on the metric, create anything from a simulated traffic spike to database failures, network interruptions, server outages, cyberattacks, or other disruptions that could interfere with the website’s uptime and performance.

The goal of these scenarios is to test the readiness of your website in the event of a real-life disaster or threat. That’s why you should stick to scenarios that are complex but realistic.

Set Up a Test Environment

Of course, you should never perform resilience testing on a live website.

Instead, duplicate the entire live system and its features, including the server configuration, database, and hardware. This will be your test environment.

A proper test environment should have the same scaling capacity as the live website. However, in the case of a website in development, perform a resilience test before launch.

Introduce and Measure Disruptions

Refer back to the failure scenarios you defined earlier. Each scenario should involve one or more specific disruptions.

Now, introduce those disruptions to your test environment to observe how your website performs under such unusual or high-stress conditions.

If the goal of the test is to verify the website’s ability to handle a traffic surge, simulate a DDoS attack or a high-traffic load testing event. This will help you determine what server resources you need to address, if any.

Test Recovery Mechanisms

If you want to be able to restore your site’s functionality following a sudden disruption, you also need to analyze the strength of its recovery protocols.

These include your site’s backup and restoration mechanisms, redundancy settings, and other downtime and recovery measures.

Monitor and Analyze Performance

As you conduct each test, make sure you’re tracking and quantifying all performance data.

You’ll need data for key resiliency factors, such as response times, server resource consumption, error rates, and other website performance metrics.

This data is what you’ll use to uncover vulnerabilities, discover opportunities to improve resilience, and determine if additional testing may still be needed.

Assess Test Results and Make Informed Improvements

Finally, use the test findings and data to create a detailed report with recommendations for how your team can improve the site’s resilience.

These recommendations may include infrastructure overhauls, code optimizations, security enhancements, or similar measures that bolster the site’s resilience.

Related: How to Reduce Costs and Increase Efficiency in Website Development with Bug Reporting Software

Examples of Resilience Testing at Established Brands

Resilience testing is a standard practice for maintaining everything from web servers to software. Below, we summarize the website and software resilience testing practices at three well-known brands.


Meta, the parent company of Facebook, facilitates the communication of over 1 billion users across its social media platforms.

Their enormous user base relies on large data centers with a 99.9 percent uptime. Because the company understands how emergencies can affect uptime, they conduct regular resilience testing to prepare for such incidents.

Meta’s resilience testing puts their data centers and server infrastructures through extreme stress tests by turning off a region, then activating and running on backup systems for 24 hours.

This approach simulates a disaster to prepare their systems and teams for critical and unexpected situations, like a massive cyberattack. Meta’s robust resilience testing is why they have the infrastructure to withstand such situations.

Despite the company’s rigid testing, however, the company recorded a 6-hour downtime in October 2021 due to a BGP and secondary DNS problem triggered by a maintenance error.

Since then, Meta has doubled its resilience testing standards. Their new standards ensure that maintenance actions are checked by an internal auditing tool before taking effect.


Netflix is known for the development of its Chaos Monkey tool that tests the resilience and recoverability of their Amazon Web Services (AWS) instances.

The tool randomly takes down one or more virtual machines to test the resilience and recoverability of the system when it is not operating at capacity.

Chaos Monkey can also simulate instance failures at specific times for easy monitoring. Today, several organizations use Netflix’s chaos engineering approach to test the resilience of their own systems.

Netflix primarily uses this tool to test the resilience of its microservices. But in spite of the streaming service’s impressive resilience testing process, Netflix went down for two and a half hours, on the eve of the launch of the “Luke Cage” series in 2016, due to undisclosed reasons. The company responded by designing a bandwidth throttling system to manage and prevent similar events from occurring.

Now, whenever there is a problem with a significant server, Netflix implements a priority-based progressive load shedding to degrade secondary services and throttle traffic based on how much bandwidth the user needs to watch their show. This prevents users from noticing system failures.


IBM’s cloud resiliency orchestration system offers a robust disaster recovery (DR) and cyber incident recovery (CIR) management approach that validates an infrastructure’s readiness for disaster incidence.

This is similar to Netflix’s Chaos Monkey. However, IBM’s resilience orchestration system provides automated DR and CIR monitoring, reporting, testing, and workflow automation capabilities for complex hybrid IT infrastructures.

The solution is available for both cloud and onsite infrastructure. The cloud solution has more automation capabilities and can execute disaster recovery testing based on user command.

Like Netflix and Facebook, IBM has had its fair share of outages. In June of 2020, IBM cloud data centers went down due to an incorrect BGP routing that resulted in severe congestion. The problem persisted for about three hours before it was resolved.

Since then, the tech firm has developed new recovery solutions to prevent similar situations from occurring.

You Might Like: How Customer Journey Mapping Informs Better Website Builds

Difference Between Reliability and Resilience Testing

Reliability and resilience are two related but distinct concepts that are used in the testing and evaluation of a website’s capabilities.

Reliability Testing

Reliability testing is the capacity for a system or website to consistently perform a specific function or service under normal conditions.

A reliability test looks at a website’s ability to operate in typical circumstances while meeting performance standards over an extended period of time.

To illustrate, a reliability assessment for an e-commerce website might test the following scenarios:

  • Load balancer tests
  • Database search response time
  • Latency and connectivity testing

Resilience Testing

As we’ve covered, resilience testing considers a system’s ability to withstand and bounce back from unplanned disruptions, core function failures, and cyberattacks while still delivering optimal and continuous service.

Unlike reliability tests, which look at a site’s ability to perform in everyday conditions, resilience tests focus on how well a site can bounce back from unexpected attacks or emergency scenarios.

It involves running a system through various disaster scenarios, such as hardware failures, network outages, or security breaches. The goal is to identify and fix vulnerabilities, as well as develop recovery mechanisms that keep the site operational and responsive.

In summary, reliability testing emphasizes consistent performance under normal conditions, while resilience testing focuses on the system’s ability to withstand and recover from adverse events. Both testing methodologies are necessary for a website’s overall fitness.

How Resilience Testing Can Help Your Business

If you own a high-traffic website or are looking to scale your current website, there are several benefits to adopting a regular resilience testing strategy.

Improves Customer Experience

Customers are happier when your website is reliable and never goes down. The faster your site’s response times, the more engagement and conversion you’ll see.

By developing a website that can handle and quickly recover from disruptions and failures, users experience uninterrupted service, a seamless browsing experience, and little to no downtime — which contributes to higher customer satisfaction and retention over the long run.

Minimizes Failure and Security Issues

As a proactive approach to tech infrastructure management, resilience testing helps minimize the probability of system failures and security vulnerabilities.

Identifying and addressing weaknesses before they become critical makes the website less susceptible to cyber attacks, data breaches, or service disruptions.

Netflix’s priority-based progressive load shedding is a real-world example of a disaster management system.

Assesses Conformity with Privacy and Scalability Standards

Resilience testing ensures a website’s features align with industry and global standards, such as the EU GDPR or US cybersecurity laws.

By validating compliance, businesses can prevent legal complications and potential fines. Also, resilience testing assesses the system’s readiness to scale and handle user surges, which optimizes resource allocation while enabling cost savings.

Performing Quality Assurance Testing With BugHerd

Website quality assurance testers work faster with BugHerd, thanks to the application’s simple UI and powerful bug-reporting features.

BugHerd’s issue-tracking features elevate how your team collaborates during development. Users can report, assign, and track bugs within the BugHerd system.

Once a bug is reported, it generates a report that is visible to every project member until the bug has been resolved. The person who reported the bug will also receive a notification once the bug has been fixed and the ticket is closed.

Open a BugHerd account to get a 14-day free trial and perform quality assurance tests on your website in development.

You can invite unlimited guests to provide feedback on the website’s features. This is great for collecting feedback from clients and end-users to make changes before launching the live platform.

Up Next: Best Online Annotation Tools for Client Feedback

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