What is Shift-Left Testing?

Shift-left testing is a software development approach that focuses on moving testing activities earlier in the development lifecycle.

5 min read
What is Shift-Left Testing? A simple concept with obvious benefits.

Shift-left testing is such a simple concept with obvious benefits, but as a result often gets overlooked. Modern development methodologies such as SCRUM bake shift-left testing into the development lifecycle and for good reason. This article outlines how this simple concept provides significant gains and dives into how you can take advantage of it today.

Understanding Shift-Left Testing

Let's start with the basics. Traditionally, software testing was a phase that occurred near the end of the development lifecycle. The development team would hand off a nearly-finished product to the Quality Assurance (QA) team, who would then spend a chunk of time testing the software to find and report any defects. This "test at the end" approach led to several problems:

Shift-left testing challenges this traditional model. The idea is simple yet revolutionary: move testing activities earlier in the development lifecycle. By starting testing sooner – ideally as early as the requirements gathering phase – we can catch and address problems when they're smaller, less complex, and less costly to fix. Don't get caught in the trap of assuming testing can only begin when there is some functioning code. QA should start right at the beginning, even before you've decided on what you're going to develop.

The Benefits of Shift-Left Testing

The benefits of shift-left testing
  1. Early Bug Detection and Cost Reduction: Finding bugs early is like weeding a garden while the weeds are small. It's much easier (and cheaper) than dealing with a tangled mess later on. Shift-left testing dramatically reduces the cost of fixing defects by addressing them at their source.
  2. Improved Code Quality: When developers know their code will be tested early and often, they tend to write cleaner, more testable code from the start. This proactive approach naturally leads to a higher-quality codebase.
  3. Faster Time to Market: Shift-left testing streamlines the development process. Instead of lengthy testing cycles at the end, testing becomes an ongoing activity. This means fewer surprises late in the game and a smoother path to release.
  4. Enhanced Collaboration: Shift-left blurs the lines between development and QA. Testers are involved from the beginning, working alongside developers to ensure that quality is built into the product from the ground up. This fosters a culture of shared responsibility for quality and leads to more effective communication and collaboration.
  5. Risk Mitigation: By identifying and addressing potential issues early, you significantly reduce the risk of critical defects making it into production. This protects your brand reputation and enhances customer satisfaction.

Shifting Your Testing Strategy

Implement a shift-left strategy

Now that we understand the compelling reasons to adopt shift-left testing, let's explore how to make it a reality in your team or organization. As previously mentioned many modern development methodologies bake a shift-left testing mentality into their processes but it's important to understand and recognize the benefits of that to ensure they are not overlooked or neglected.

Embrace a "Quality First" Culture

Shift-left testing is not just a process change; it's a cultural shift. Everyone on the team, from developers to product managers, needs to be invested in quality. I often talk about fostering a culture of collective responsibility and software quality is at the center of this movement. Everyone on the team should feel responsible for the quality of the product that is ultimately delivered to end users. When everyone is consciously thinking about software quality it'll be much easier to get your QA team involved earlier in the process.

Start Early and Test Often

QA starts as soon as there is any form of tangible requirement. Don't wait until the requirements are well defined to get your QA team involved, more often than not an experienced QA team will quickly identify glaring holes in the requirements, and by having QA involved in defining initial feature specifications you'll save a lot of time up-front. Once you've got well-defined feature specifications ensure they're broken down into individual, testable components to ensure you're testing several times throughout the development cycle. This iterative approach ensures you're catching smaller issues early as opposed to catching large problems late.

Automation in Key

Automation is your best friend when it comes to shift-left testing. Invest in automated testing tools and frameworks that can run tests quickly and frequently. This is essential for catching regressions early and providing rapid feedback to developers. There are so many automated testing tools available it's hard to know where to start, especially if you don't already have skilled automation engineers on your team. If your products are mobile-based I can highly recommend Maestro, it's easy to pick up and it really does "just work".

Empower Developers

Empower developers with the responsibility to implement and maintain static code analysis tooling, unit tests, integration tests, and UI tests. This empowers them to take ownership of quality (once again touching on the importance of collective responsibility within the team) and catch issues before they even get to the QA team. This may require additional training to help your development team acquire these new skills, it's doesn't need to be expensive either, there are plenty of well-designed courses available via online platforms such as Udemy or Pluralsight and you'll quickly get a return on your investment.

Continuous Feedback and Collaboration

Establish a continuous feedback loop across the entire team. Encourage open communication and collaboration to resolve issues quickly and efficiently. If each member of your team truly feels the collective responsibility to deliver a high-quality experience to your end users you'll find this happens almost naturally.


It's important to remember that shift-left testing is a journey, not a destination. It takes time, commitment, and a willingness to adapt and learn. But the rewards are worth it. By embracing shift-left testing and a culture of collective responsibility you can dramatically improve the quality of your software, accelerate your development cycles, and ultimately deliver more value to your users.

Don't underestimate the power of this seemingly simple shift. Whether you're a startup or an established enterprise, implementing shift-left testing can transform your development process and ultimately drive greater success for your business. It's time to embrace this paradigm shift and reap the rewards of a quality-first approach.

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