When to use end-to-end testing? Use cases and examples

In software development, every step counts. From designing to coding, checking for bugs to launching, each part helps make a good end-product. While many companies and businesses understand the gist of it, many miss one important step - end-to-end testing.

More than 50% of users would fully quit the app if they came across one or more bugs during a single day of app usage.

This shows how important it is to test from the user’s point of view to make certain everything works like a well-oiled machine.

In this article, we will explain in simple terms what end-to-end testing is and how it fits with other types of tests. We will also provide practical tips for implementing it effectively and share KPIs to measure its success.

Before diving into specific scenarios or best practices, defining what end-to-end testing entails in the broader testing pyramid is essential.

What is end-to-end testing? All you need to know in a nutshell

Imagine software is like a road trip. Small tests check the engine, others ensure the GPS is working properly, and some verify you have the right tires for the terrain. End-to-end testing, however, checks the entire trip from start to finish. It ensures the car runs smoothly, you have enough supplies, and all the maps are up-to-date.

Unlike more straightforward testing methods, end-to-end (E2E) testing focuses on the entire user journey. It mimics the user's experience from beginning to end, verifying that all components work together as expected, ensuring a seamless interaction with the system.

Imagine a shopping application where a user does the following steps:

The end-to-end testing example above presents a scenario in which every step is validated. Experts use e2e tests to make sure data transitions correctly across different system layers, from front-end to external APIs.

Check out our What is E2E testing? A complete guide to compare E2E with other methodologies to validate the user journey and avoid costly mistakes.

Ultimately, end-to-end testing offers excellent visibility into your software's behavior when mimicking real-world conditions. Instead of simply testing the end product for bugs, you go through the entire user journey bit by bit, finding even the most minor issues that can thwart user experience. While it can sound hard, it is worth it in every given case. Namely, because end-to-end testing is essential, we will discuss further.

The importance of end-to-end testing in the software development cycle

Software ecosystems do not exist in isolation. They are like bustling neighborhoods constantly talking to

These connections create a web of interdependencies. In this scenario, end-to-end testing is a neighborhood watch. The model makes sure every system communicates correctly and data moves smoothly. That’s where end-to-end testing test best practices shine. In short, the practice simulates actual user paths and keeps a firm watch on system-wide functionality.

Why End-to-End testing best practices matter

From the top of the head, end-to-end testing framework matters because of these three reasons:

When end-to-end testing is done correctly, it brings a smooth and high-quality user experience. Moreover, the practice protects your brand’s reputation and helps avoid costly mistakes in the future. Finally, e2e tests are a great way to avoid hefty non-compliance fines.

When is the best time or conditions to use end-to-end testing?

E2e testing is a powerful tool. However, it is not a one-size-fits-all solution. The approach is a perfect fit for complex systems with many moving parts. However, if you have a simple product on your hands, end-to-end testing might be an overkill.

In other words, end-to-end testing delivers huge value as it verifies how everything within a product works together. Naturally, to deal with such a complex task, the practice needs to be resource and time-intensive. Use end-to-end testing strategically. Consider these scenarios to get the best cost-to-quality ratio.

Scenario #1. Complex applications and multiple modules involved

Every product might exist or be exposed to high-complexity environments. For instance, microservice architectures or systems involving different third-party APIs can be considered high complexity. These require additional focus on more comprehensive verification. Even the slightest chance in microservice can influence the entire product. By running e2e tests, you can quickly validate data flow and detect unforeseen interactions.

For instance, imagine a fintech app with multiple modules, including user accounts, payments, transaction history, and notifications. E2E testing ensures that the data remains consistent across all these modules. The process checks every step of the journey, from the user's first action to the final database entry, making sure everything is functioning as expected.

Scenario #2. Critical user journeys which can't be ignored

When user action and satisfaction are the key aspects impacting your brand’s reputation and product’s success, checking all user flows with the utmost caution is vital. Even minor bugs in payment gateways or registration processes can significantly harm user trust.

Scenario #3. Strict regulatory or compliance conditions

Organizations cannot afford partial verification or partial compliance. When a company or a business operates in the industry under the need of constant HIPAA compliance testing, PCI-DSS, or GDPR constraints, compliance begins playing one of the key roles.

In such a context, end-to-end test cases certify every step, from data collection to storage, follows mandated guidelines. Ultimately, your product will be more compliant, and you will avoid hefty fines.

Consider partnering with a specialized provider offering verified end-to-end testing services to guarantee reliable results throughout the software development cycle. Having external expertise can play a significant part in verifying your approach. While the vendor does their best to deliver top-notch testing, you can focus on strategic growth and be sure the product will be on the market without any delays.

Scenario #4. Major system changes and alterations

Major updates can cause disruption. When you are in the middle of a major update, a new feature launch, or a merger, these alterations can significantly impact the product’s performance and reliability. When the changes occur, conducting end-to-end testing is a chance to keep everything stable in times of turmoil.

E2e testing is not a one-size-fits-all solution. When you deal with complex architecture, essential transactions, compliance matters, and post-release alterations, e2e testing will significantly help. Yet, you need to understand that the benefits of the practice are not limited to the scenarios we mentioned above. Those are the cases when e2e tests yield the most value.

The art of balancing end-to-end testing with other test types out there

A smart testing strategy is like building a house with several layers of protection.

Each layer catches different flaws, creating a stronger and more reliable result. Balancing these types wisely can minimize costs, speed up feedback loops, and maintain robust coverage.

Now, exploring different types of tests is crucial for understanding the essence of the process and end-to-end testing.

Type #1. Unit Tests

Unit tests target single classes, functions, or methods. They’re simple to run, fast, and help developers locate problems immediately.

Where does it fit best? Use unit tests to validate small pieces of logic that would be cumbersome to check in an entire e2e testing run.

Pro Tip: Keep unit tests abundant since they provide immediate feedback efficiently. This ensures that small mistakes don’t snowball into more significant issues downstream.

Type #2. Integration Tests

Integration testing monitors whether combined modules (e.g., front-end logic calling a back-end endpoint) function correctly.

Key purpose? They fill the gap between the unit and e2e by confirming the handshake among components without simulating the entire user flow.

Pro Tip: If you want more detail on how these differ from e2e, read five differences between integration testing and end-to-end testing, clarifying each test layer's boundaries.

Why relying too much on e2e tests can be detrimental

Leaning heavily on end-to-end tests can backfire:

While end-to-end testing is essential for validating real-world user flows, it cannot replace unit or integration-level granular checks. Strive to create a balanced pyramid of tests, where E2E is the apex.

3 end-to-end testing best practices for better software development cycles

Building compelling end-to-end test cases requires a deliberate approach. Rushing into e2e without proper planning can provide flaky tests.

To craft solid end-to-end tests, follow these steps:

1. Plan ahead with automation

Manual approaches work for exploratory or ad-hoc checks. However, consistent coverage demands automation. Automated scripts integrated with CI/CD enable daily or per-commit runs.

End-to-end testing framework: Tools like Selenium, Cypress, and Playwright support scripting for multiple browsers or devices. For a detailed comparison, consult the Pros and cons of end-to-end testing tools.

2. Prioritize and set critical paths

It’s unrealistic to replicate every click a user could ever make. Focus on critical user journeys.

Why does it matter? By zeroing in on essential flows, you maximize the return on each test and minimize unnecessary upkeep.

3. Keep maintainability in check

Large e2e test suites can quickly become fragile, especially in agile environments. Use design patterns (like the Page Object Model) to centralize element selectors. Keep test logic modular.

Pro Tip: If your team often modifies front-end elements, a well-structured test suite is more straightforward to update without rewriting everything.

Using best practices, automatic checks, and focusing on key journeys will make your end-to-end process examples efficient and strong. But, issues like test flakiness or environment mismatches can still happen. So, you must be aware of some common challenges to balance effectively.

3 most common challenges in conducting end-to-end test cases

Even great end-to-end tests hit snags sometimes. You can have even the best e2e tests at your disposal. However, no matter how flawless the practice is, end-to-end testing still can face some obstacles.

These often derail timelines and can undermine overall results. In such a case, let’s look at the three most common challenges in end-to-end testing to understand better how to avoid these in the future.

Challenge #1. Test flakiness or unpredictability

Flaky tests pass or fail unpredictably. This often happens due to timing issues, network latency, or asynchronous processes. All of these are not accounted for in the script.

Potential solution: Implement wise waits and mock external services. Stabilize your tests.

To get a deeper grasp of the potential challenges, please refer to this piece: Common challenges in end-to-end testing and how to solve them. It is an easy read that dives into common root causes and advanced prevention tactics.

Challenge #2. The problem with slow execution

More enormous test suites can hog time. Continuous Integration pipelines may bottleneck if e2e test runs take too long.

Potential solution: Parallelize runs using Docker containers or specialized cloud platforms. Keep tests focused on critical paths to trim unnecessary checks.

Challenge #3. Exposure to complex test environments

End-to-end testing often needs to replicate production-like conditions:

Discrepancies between environments can lead to misleading test results.

Potential solution: Employ infrastructure-as-code to replicate configurations precisely. Keep your test environment as close to production as possible.

Addressing these hurdles proactively allows you to maintain a high-performing e2e regimen.

Next, we’ll highlight popular tools and frameworks for end-to-end testing. The key idea is to explain how they can simplify script creation and environment setup.

Most popular tools and frameworks for end-to-end testing

Picking the right tool for end-to-end testing is like choosing the perfect hiking gear. Yes, we are still on our first road trip example. In hiking, the terrain is everything. Some tools shine for web apps. Others for mobile or performance testing. The key is to match the tool to your project needs. If done correctly, your testing will run smoothly and catch what matters the most.

Popular options among end-to-end testing frameworks

Here are three standout frameworks:

1. Selenium

Highlights: Mature ecosystem with broad language support.

Use case: Versatile for web apps where a multi-language approach is needed.

Next step: Pair Selenium with a test runner (like JUnit or TestNG) to structure your suite efficiently.

2. Cypress

Highlights: JavaScript-based, real-time reloading, and straightforward debugging.

Use case: Modern web apps where front-end reactivity demands deeper browser-level insights.

Next step: Check out How to start end-to-end testing with Cypress. Suppose you’re exploring a JS-focused solution.

3. Playwright

Highlights: Playwright provides multi-browser support (Chromium, Firefox, WebKit) and excellent concurrency.

Use case: Teams seeking cross-platform coverage in a single tool.

Next step: For advanced configurations, see Guide to Playwright end-to-end testing.

Getting the most of innovation with AI-enhanced tools

A rising trend involves AI-based solutions that adapt to minor UI changes. They may automatically generate or update scripts based on observed user paths. For more insights, see Proven approaches to utilize AI-powered e2e testing.

Choosing a framework depends on your tech stack, team skills, and app complexity. The right tool speeds up test creation and execution. It also reduces maintenance issues.

Metrics for measuring end-to-end testing success

Defining and tracking the right metrics is integral to refining your end-to-end testing approach. Without data, you can't tell if your tests are helpful or just creating extra work.

KPIs to keep in mind

When measuring the success of end-to-end testing, it is essential to use some well-established measures and KPIs. Ultimately, consider these:

1. Coverage across critical flows

Assess whether your tests encompass the user scenarios most important to your business. For example, if your most significant revenue driver is an online checkout, ensure the entire transaction path is fully validated.

2. Execution time

Extended e2e test runs slow release cycles. Monitor average test duration. To avoid pipeline bottlenecks, keep these tests under a reasonable threshold (e.g., under 15–20 minutes in CI/CD).

3. Test reliability

Evaluate how often tests fail due to bugs versus flakiness or environmental inconsistencies. A well-maintained suite should have minimal false positives.

4. Defect discovery rate

Track how many critical issues E2E catches before production. Consider revisiting your test scenarios if production incidents keep slipping through.

For step-by-step instructions on structuring robust test scenarios, see how to build E2E test cases. The piece covers scenario planning, test data management, and case maintenance.

By regularly analyzing these metrics, you can fine-tune your approach to maximize the return on investment.

The appearance of end-to-end testing in the cloud environment

Running end-to-end testing in the cloud offers unparalleled flexibility and scalability, freeing teams from on-premise hardware constraints. Cloud-based platforms can make the testing workflow much smoother. They provide real-time analytics, run tasks in parallel, and have global coverage.

Notable cloud-native tools and environments to consider

Platforms such as BrowserStack, Sauce Labs, or AWS Device Farm provide on-demand setups where you can spin up real browsers web QA testing or testing for mobile apps within seconds. This approach clarifies end-to-end process examples on varied OS/browser configurations without maintaining your device lab.

Real-time and parallel testing

Cloud solutions often enable parallel runs, dramatically cutting execution times. Instead of sequentially testing each user path, multiple tests can proceed simultaneously. To illustrate, 50 end-to-end test cases can be split across 5–10 parallel nodes, finishing in a fraction of the time.

Moving e2e testing to the cloud can change your testing process. It helps you manage demand spikes and test different user environments on a larger scale.

Conclusion

End-to-end testing is a cornerstone of testing. It is like a final safety check before launch. E2e tests help you look at the bigger picture. You make sure complex systems and user journeys hold up under pressure. It is a good practice to pair end-to-end testing with smaller tests for a foolproof approach.

Key takeaways:

In a scenario where user expectations are rising, ensuring performance and reliability match those is crucial. In such a case, end-to-end testing is important for matching performance and reliability with user needs.

With reliable partners like DeviQA, your businesses or companies can release software that meets certain technical standards.