A Deep Dive into End-to-End Testing in Software Testing

July 21, 2023

A Deep Dive into End-to-End Testing in Software Testing

Research is done by Rhea

Software testing is the process of evaluating and verifying that a software product or application does what it is supposed to do. Software developers and testers desire to create applications free of bugs and errors. Integrating several features within the software system requires more than system and application function testing. So, End-to-end (E2E) system testing was developed to overcome the limitations of other testing procedures.

What is End-to-end Testing?

E2E is a type of software testing technique. It is the testing methodology that validates a software workflow from start to end. The primary goal of E2E testing is to simulate an end user’s application journey and ensure that all integrated components, dependencies, and other integrated pieces work as expected.

Why is end-to-end testing important?

Conducting end-to-end testing helps ensure your software is production-ready, layer by layer. E2E tests allow us to cover sections of the application that unit tests and integration tests don’t cover. This is because unit tests and integration tests only take a small piece of the application and assess that piece in isolation.

Even if these pieces work well by themselves, you don’t necessarily know if they’ll work together as a whole. Having a suite of end-to-end tests on top of unit and integration tests allows us to test our entire application.

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Types of End-to-End Testing

There are two main types of end-to-end testing: horizontal and vertical. These two types of testing differ in their scope and focus.

Below are the definitions of the two types:

Horizontal end-to-end tests

When it comes to “end-to-end testing,” horizontal testing is what immediately comes to mind for the end user. This approach places emphasis on testers ensuring that each individual workflow in the application functions flawlessly.

For instance, for an e-commerce store, this would include testing a user’s journey from the registration page to the checkout process, then all the way to receiving their purchase confirmation. If any step fails during the test, it is considered a test failure.

Essentially, this type of testing is focused on validating the functionality of the application from start to finish.

Vertical end-to-end tests

Vertical testing takes a dive into the technical depths. It’s what testers envision when they hear the term “end-to-end testing”. While end users only encounter the front end, testers venture into the back end as well. Their mission: ensuring seamless data transfer and leaving no room for doubt.

A scenario for a vertical end-to-end test would be to ensure that each layer of the software stack is functioning correctly. This includes checking multiple components, like databases, web servers, API layers, and more.

The End-to-End Testing Lifecycle

End-to-end testing serves the purpose of identifying system dependencies and ensuring seamless integration of data across multiple systems. Below is an outline of a typical end-to-end testing lifecycle:

1. Test planning

The test planning phase occurs after the completion of integration testing. During this phase, a test plan is created, outlining the objectives of the testing process based on the user expectations, initial client requirements, and application architecture.

2. Test design

The next phase involves test design, where a suitable testing environment is established in accordance with the requirements. Testers then have established test environments and proceed to craft the essential test cases, leveraging automation testing tools to streamline the test design process and minimize time consumption.

3. Test execution

During this phase, both local and remote test cases are executed. It is important to closely monitor the progress of the tests across multiple test cases to ensure consistency with the original test plan.

4. Results analysis

Finally comes the stage of result analysis. During this phase, the test results are carefully examined to identify the root cause of the bug.

a programmer testing software

The Pros of E2E Testing

Software testing has been the norm for a while, and having the ability to test end-to-end makes it easier for organizations to release quality software faster.

Whether you aim to conduct unit, user acceptance testing, or functional tests, here are the advantages E2E testing offers:

Tests from a user’s perspective

Naturally, an end user’s perspective is very different from the perspective of developers and testers. Conducting end-to-end testing enables organizations to simulate user behavior and understand the parts of the software that could be optimized.

Verifies workflows

There are several real-world scenarios that can take place in an application, and end-to-end testing verifies each of them. Understanding the entire workflow helps ensure that all user functions and features work correctly together to provide a great user experience.

Expands test coverage

By integrating various subsystems into your testing process, you can significantly broaden your test coverage and generate additional test cases that may have been overlooked in the past. This approach enhances the quality of your testing and ensures a more comprehensive evaluation of your entire system.

Reduces the number of errors found in production

End-to-end testing is crucial for identifying and resolving issues promptly during software development. You can minimize the chances of bugs progressing into production by conducting thorough testing at each iteration. This comprehensive approach ensures seamless application workflows and reduces the need for repetitive testing, saving time and costs in the long run.

The Cons of E2E Testing

While conducting an end-to-end test improves quality and reduces the number of errors found in production, there are some drawbacks:

Slow execution

Executing this testing process require patience and time, taking weeks or even months. It’s a meticulous and intricate endeavor, demanding absolute thoroughness and precision in every step. But fear not, for these efforts will ultimately bring forth the desired outcome.

Fragile/flaky tests

End-end tests need maintenance and troubleshooting. But there’s a reason for it—they simulate real-world scenarios, interacting with different system components. Ensuring test suites and their continuous effectiveness and reliability requires diligent monitoring, periodic updates, and meticulous problem-solving.

Lack of available test environment

Test cases can only be accurately executed when the right test environment is available. A lack of one often translates into inaccurate and unreliable test results, which ultimately defeats the purpose of conducting end-to-end testing.

More difficult to debug

When an E2E test fails, debugging can be more challenging compared to unit or integration testing. E2E testing requires thorough research and investigation to uncover the underlying issue. This involves examining multiple system components and interactions, making debugging captivating yet time-consuming.

Popular End-to-end Testing Tools

Automated tests are the most efficient way to conduct end-to-end testing. However, manual testing still has its place when you need a more detailed assessment. It all depends on the type of testing you need to execute.

These are some of the popular E2E automation testing tools in the industry:


Cypress is an end-to-end testing solution for modern web applications. With its new file runner, executing tests and accessing up-to-date file versions is easier than ever. It’s written in JS and node, requires no build steps or dependencies, and offers a unique browser-based testing architecture for faster and more stable results.

Here are the quick steps on how to use the Cypress E2E testing framework:

> npm install cypress

> npm run cypress:open

> npx cypress run –record –key keyValue

Components Testing:

Cypress components testing

E2E Testing:

Cypress E2E testing

Example of Testing Results:

Example of Cypress testing results


Selenium is the go-to tool for testers when it comes to cross-browser testing. It lets you test on different browsers and operating systems and supports various programming languages for building tests.

Selenium IDE

What is the difference between Selenium IDE and Webdriver?

Selenium IDE is a tool for recording and playing back test cases, while Selenium WebDriver allows for writing test cases programmatically. WebDriver is the preferred industry automation testing tool, working on all browser platforms and supporting multiple programming languages. On the other hand, IDE has limitations in test case development, as it is limited to Firefox and lacks programming language support.

Selenium WebDriver

Here are the quick steps on how to use Selenium Webdriver:

> install selenium-webdriver 

> node tests/sample.js

What is Selenium Grid?

The Selenium Grid is a powerful testing tool that empowers us to execute tests on diverse machines across various browsers. As a valuable component of the Selenium Suite, it excels in seamlessly running multiple tests across different browsers, operating systems, and machines.

Selenium Grid Architecture

Below are the commands to get started with Selenium Grid:

> java -jar selenium-server-4.9.0.jar hub

> java -jar selenium-server-4.9.0.jar node –hub

> java -jar selenium-server-4.9.0.jar node –hub –port 5556

> java –Dwebdriver.ie.driver=”path to browser exe file” –jar selenium-server-4.9.0.jar node –hub

Selenium Grid code
Selenium Grid
Selenium Grid testing
Selenium Grid projects


Puppeteer is a popular Node.js library developed by Google that provides a high-level API to control and automate Chrome and Chromium browsers. It is often used for end-to-end testing of web applications and for web scraping tasks.

Here are the quick steps on how to use Puppeteer:

> install jest & puppeteer with npm

> npm run test / yarn test

Puppeteer end-to-end testing


End-to-end tests can be very time-consuming to create and maintain. The time taken depends on the complexity of the application and the number of test cases that you have to execute. But they can help you to ensure that the application performs all of its functionalities as specified before releasing it to production.

Tools for automated testing are also made available, which can help to execute tests and reap the benefits of end-to-end testing quickly. A combination of manual and automated tests is often found to be ideal for ensuring maximum coverage of test cases. Additionally, following best practices such as data management, collaboration with stakeholders, and prioritization of critical workflows will ensure that you get the most out of your E2E testing!

Need to Hire Quality Assurance Developers for E2E Testing?

Embrace the mindset of considering end-to-end testing as an indispensable component of the testing pipeline. It’s a game-changer that fuels confidence and ensures the robustness of your application.

StarTechUP can provide you with expert QA engineers on board so you can rest assured issues and risks are prevented early in the development process. We’ll provide you with all the systems and necessary resources to conduct efficient and effective user interface (UI) and user experience (UX) end-to-end tests!

Get in touch today to learn more about how we can help your business succeed. Our team of experienced QA professionals is excited to work with you!

About the author: Andrea Jacinto - Content Writer

A content writer with a strong SEO background, Andrea has been working with digital marketers from different fields to create optimized articles which are informative, digestible, and fun to read. Now, she's writing for StarTechUP to deliver the latest developments in tech to readers around the world. View on Linkedin