Testing Pyramid: Breaking Down the Layers

Kassidy Kelley , Managing Editor

February 28th, 2022

Teams often look to general frameworks, like the test automation pyramid, to dive into building their automated testing strategy.

The test automation pyramid framework ensures faster feedback, better test coverage, and a more maintainable automation suite. The pyramid consists of three layers: Unit Tests, Integration Tests, and End-to-End (E2E) Tests. Each layer has a specific purpose and requires a different testing approach.

Table of Contents

• What Is the Test Automation Pyramid?
• The Importance of the Test Automation Pyramid 
• The New Test Automation Pyramid
• Including the test automation pyramid into your workflows
• Final Thoughts

What Is the Test Automation Pyramid?

The Testing Automation Pyramid is a framework designed to help both developers and QA teams create high-quality software. It helps developers quickly identify if a change they’ve introduced has broken the code, contributing to a more reliable test suite.

Also known as the Test Pyramid, this model defines the types of tests you should include in an automated suite. It also outlines the sequence and frequency of these tests. The primary goal is to provide immediate feedback so that new code does not disrupt existing features.

While the test automation pyramid offers a simple framework, its lack of context can make practical implementation challenging. One common pitfall is the assumption that all elements of the pyramid should be implemented with the same granularity and frequency, which is not the case.

The test automation period works in three layers.

1. Unit Tests – At the top of the pyramid
2. Integration Tests – The middle layer
3. End-to-End Tests – The bottom, largest layer of the pyramid

Let’s break down the components of the automated testing pyramid to see where you need to really focus to succeed with this framework.

The ultimate tip: Use the pyramid as a guideline to testing layers and NOT a hard and fast rule. You still need to put in the legwork to define and create your own automation framework that works for your DevOps team. 

1. Unit Tests

Unit tests are your entry point, and the main focus of an immature test automation strategy. Automate these tests quickly and abundantly. Unit tests isolate and validate specific features to ensure functionality – think smoke tests, regression tests, and configuration tests. Define the parameters of “units” with your internal testing teams, since most will have varying ideas of what individual units look like. Generally, unit tests should be tests that are already broken down into specific micro-units and are relatively straightforward without any external dependencies (they are mocked or stubbed out).

Remember, automated unit tests run in isolation so they can be shifted around an automated test suite or toggled on/off as needed. Combine units to create an automated unit test suite, a collection of certified tests that assures success under normal conditions. A good test suite is stable, manageable, serves a breadth of functionality, and is fast with a clear context for developers. 

Besides the clear benefit of simplicity and high ROI, automating unit tests identifies functional issues in individual modules allowing devs to quickly fix code. Testing feedback is nearly immediate, and unit tests are often stable from run to run. After identifying unit tests to automate, developers use a test-driven development methodology to approach builds systematically.

Dev teams following the test automation pyramid strategy face a major problem with the base layer: developing automated unit tests immediately creates faster test runs, but since this pyramid section is so large, too many automated unit tests that fail can slow down the testing cycle. As your product grows and more features are added, unit tests increase, and the pyramid base gets larger and larger. A solution? Don’t test trivial code, production code, and only automate tests with clear, observable behaviors. 

Use a test methodology (like TDD)

Super simple frameworks like the test automation pyramid benefit from implementing a structure that unifies designing, building, and testing code. Here’s an example of the benefit of using a testing methodology, like test-driven development (TDD). 

When automating with the TDD methodology, devs automate existing code and only create new code if the automated code fails the test. This strategy quickens the automation process; devs are not creating new scripts for every unit test but working with existing code to automate tests before developing functional build code.

Start with the code you have. Run automated unit tests and see what passes and fails to provide results. If the code passes, great! You’ve automated your unit test. If it fails, develop new code and rerun it. 

Following TDD looks like this: 

• Write. Create a test case module with data. 
• Code. Write just enough production code to fill the test and pass.
• Refactor. If the code breaks or fails, fix the code as needed locally.

TDD is critical to automating unit tests, as it requires devs to think through a specific use case and test before building and shipping code. TDD urges developers to start with small unit tests and write simple scripts to automate (that pass!) before heading back to refactor, a key CI/CD pipeline element. 

2. Integration Tests 

The test automation pyramid uses “service tests,” most commonly meaning integration tests. Again, defining what exactly “integration tests” are and the boundaries of integration testing are crucial steps to getting your team automating with intent. Touch on topics like: 

• Are we testing the ENTIRE stack against other applications within the system? 
• Are we going narrow, and testing individual integration points one at a time?
• Are we only going to automate integration tests we can perform locally?

As the second layer of the pyramid, integration tests are a vital yet more complicated process to automate. Once your automated unit testing suite runs smoothly across product and dev teams, you can move toward automating unit integration tests. Don’t assume integration tests can be automated with the same frequency and speed as unit tests. For one, they take longer. There are also a variety of integration components that you need to cover. Are you running integration with specific databases? Filesystems? Internal and external APIs?

For help creating an integrated testing strategy, drop us a line.

All of that needs to be covered in test cases and test scripts. Still, with so many variables, you need a roster of talented manual testers to oversee integration and validation. Run tests parallel to each other. Once your unit tests are complete and perfected, feedback should take minutes. As that’s being run, a manual tester can start an automated integration test. QE’s can then analyze unit pass/fail and integration pass-fail. If your units are up to date and functional, unit testing will pass while waiting for integration tests to run. If both fail, manual testers can analyze flags and get results back to devs.

3. End-to-End (E2E) Testing Process

If you haven’t noticed, the simplicity of the test automation pyramid makes it difficult to define what each segment is truly referring to. The top of the pyramid, UI tests, are often conflated with end-to-end testing because most UI tests are done by running your app through the E2E process. 

A pyramid hack is to run UI tests without running E2E tests. Separate out individual UI and write unit tests to test your frontend code with programs like Nunit and Selenium. UI tests are harder to automate: that’s why they sit nestled at the top. For so many teams that decide UI = E2E, automation means notoriously flaky and false-positive results. Automating E2E testing workflows reach a bottleneck when false-positive results need to be manually debugged, again and again. Amidst a talent shortage if you’re team doesn’t have enough skilled quality engineers, automating end-to-end processes is costly, incredibly long, and very fragile. 

In my test automation pyramid, E2E tasks would be an even smaller tip of the iceberg; use them sparingly, and don’t expect them to provide high ROI, better speed, or be helpful. Instead, center your team on the lower blocks of the pyramid. Extend your definition of unit or integration tests, or improve your test code.

By automating individual tests and taking an optimized approach, you can wield the talent to pick tasks with the highest impact potential. Like most agile processes, following the test automation pyramid encourages teams to iterate quickly and efficiently and create smarter systems, but this framework is not without pitfalls.

Focus on creating and establishing definitions, boundaries, and best practices that work for your team and create better, smarter processes.

The Importance of the Test Automation Pyramid 

The test automation pyramid helps you build a strong and efficient testing strategy. It ensures fast feedback, improves reliability, and makes maintenance easier. 

By structuring tests into three layers—unit, integration, and end-to-end (E2E)—you can optimize resources and improve software quality.

At the base, unit tests run quickly and provide immediate feedback. They focus on small code components, helping developers catch bugs early. Because they are easy to maintain, they form the foundation of a stable testing process.

In the middle, integration tests check how different system components work together. They help you identify issues with APIs, databases, or services. These tests take longer to run but are critical for verifying system interactions.

At the top, E2E tests simulate real user behavior. They check how the entire system performs but are slower and more complex. 

Too many E2E tests can create bottlenecks, increase maintenance efforts, and slow down releases.

Following the test automation pyramid keeps your testing process balanced. It prevents inefficiencies, reduces false positives, and ensures your automation efforts focus on high-value tests. 

HeadSpin warns that over-relying on UI or E2E tests increases costs and delays. TheCTOClub highlights that strong unit and integration testing leads to more resilient applications.

By using the test automation pyramid, you create a scalable and effective testing process. You get faster feedback, better defect detection, and a smoother CI/CD pipeline. 

Focus on building a solid foundation, and your team will deliver higher-quality software with confidence.

The New Test Automation Pyramid

Software testing has evolved. The traditional test automation pyramid focused on unit, integration, and end-to-end (E2E) tests. 

While this structure worked, modern testing demands a more flexible approach. The new test automation pyramid adapts to these needs, making automation more scalable and efficient.

The updated pyramid includes additional layers. It doesn’t rely solely on unit tests. Instead, it incorporates business process automation, low-code/no-code testing, and AI-driven testing. These innovations make automation faster and more accessible.

Take a financial services app as an example. In the old model, most tests would focus on unit and integration levels. 

But the new pyramid expands testing. Automated business process testing now verifies full transaction workflows across different systems. 

Low-code tools allow non-developers to contribute without complex coding. AI-powered test maintenance keeps scripts updated as the app changes.

This new structure reduces reliance on slow, fragile E2E tests. It ensures broad test coverage while improving efficiency. You can integrate it smoothly into your CI/CD pipeline, automating complex workflows without excessive scripting.

By adopting this modern approach, your team gains speed, accuracy, and maintainability. The new test automation pyramid helps you balance traditional testing with cutting-edge automation. 

It ensures long-term success in software quality assurance. If you want better, smarter testing, it’s time to update your strategy.

Including the test automation pyramid into your workflows

Integrating the test automation pyramid into your development workflow requires a clear strategy. 

You need to build a structured testing approach that balances speed, reliability, and coverage. Here’s how:

Start with Unit Testing

Unit tests form the foundation of the pyramid. Encourage developers to write unit tests alongside new code. 

Test-driven development (TDD) can help enforce this practice. Writing tests first improves code quality and ensures that every function behaves as expected.

Focus on Integration Tests

Once unit testing is in place, move on to integration tests. These tests verify how different components interact. 

They help bridge the gap between unit tests and end-to-end (E2E) tests. Prioritize testing APIs, databases, and other critical system connections.

Strategically Implement E2E Tests

E2E tests take time and resources, so use them wisely. Focus only on critical user journeys and essential functionalities. Avoid overloading your test suite with unnecessary E2E tests, as they can slow down the pipeline.

Regularly Review and Adjust

Testing needs evolve as your project grows. Regularly assess test effectiveness and refine your approach. Add tests where gaps appear, and optimize existing ones to maintain efficiency.

Automate and Collaborate

Leverage automation tools like CircleCI to streamline test execution. Automation ensures tests run consistently and catch issues early. 

Educate your team on the test pyramid’s importance. Encourage collaboration between developers, QA engineers, and other stakeholders to maintain a strong test suite.

Final Thoughts

Effective test automation requires the right strategy, tools, and expertise. Whether you’re just starting with automation or refining your existing process, 

Testlio provides the support you need. With a structured approach like the test automation pyramid, you can build a faster, more reliable, and scalable testing framework.

Testlio’s test automation solutions help you optimize your testing workflows. Our platform integrates seamlessly with CI/CD pipelines, ensuring continuous and efficient testing. 

We focus on balancing unit, integration, and end-to-end (E2E) testing, so your team gets fast feedback without unnecessary delays.

Automation should simplify testing, not complicate it. Discover how Testlio’s expertise can help you eliminate bottlenecks, reduce flakiness, and improve test coverage.