In recent years, the adoption of Test-Driven Development (TDD) has spread across software development teams worldwide. Popularised by Kent Beck, the practice gained traction as teams scaled its use. However, TDD's adoption has sparked ongoing debates. Influential voices in the software community, like Martin Fowler, have questioned its efficacy, as highlighted in the Is TDD Dead? discussion.

Despite the challenges, a wealth of books, courses, and learning materials have emerged, supporting a broad range of languages and frameworks—from C# to JavaScript, backend to frontend. Tools such as JUnit, Testing Library, and Jest have become foundational in the test automation landscape, whether or not developers strictly adhere to TDD principles.

TDD has also drawn attention from academia, leading to empirical research that highlights benefits like bug reduction. However, some advantages, such as improved code design, remain debated and less concrete. Still, the state of the TDD practice has yet a need for data.

Addressing the Data Gap

Since TDD's inception, there has been a lack of comprehensive data collection on its actual usage and impact. Most of what we know comes from influencers and respected professionals who advocate for TDD based on their own experiences. While their success stories have inspired adoption, there has been little data-backed insight to guide the broader industry.

That's where The State of TDD Survey comes in—to provide software professionals with data-driven insights into TDD practices and trends.

A Brief History of Our Survey

• 2021: Our first edition started as a small initiative to understand how developers were adopting TDD and what challenges they faced. It helped us identify common practices and anti-patterns—behaviours that hinder TDD effectiveness.

• 2022: In the second edition, we expanded on these findings, diving deeper into both the successes and struggles teams experienced while implementing TDD. We uncovered valuable insights about the conditions under which TDD thrives and where it falls short.

• 2023: No data was collected. This break gave us time to reflect on our previous findings and strategies on how to improve the next edition.

How We Collect Data

We use a survey-based approach, gathering responses anonymously. All data is aggregated and analysed to identify trends, challenges, and best practices in TDD. The results are published in an open-source report, freely available to the community. We do not share or sell individual responses, ensuring privacy and trust.

The 2024 edition

We’re excited to introduce the biggest and most ambitious edition of the TDD survey to date. This year’s survey aims to paint an even clearer picture of TDD adoption and its impact on the industry.

Take the Survey Now!