Look inside Lean TDD

Lean TDD is a short, practical book for developers who want the benefits of TDD without the waste. It looks at where common TDD advice goes wrong, replaces ceremony with Lean thinking, and shows how to build a test strategy around acceptance criteria and behavior-focused tests.

If you want a quick feel for the tone and approach, there is also a short sample chapter PDF below. The main edition is available now on Amazon.

  • 125 pages ebook, 101 pages print
  • Kindle and paperback editions
  • Behavior-focused testing strategy
  • Guidance for working with AI agents

Move faster

Learn a version of TDD that reduces wasted effort, shortens feedback loops, and helps you ship with less friction.

Test behavior

Build tests around acceptance criteria and observable system behavior instead of over-investing in brittle implementation details.

Work with AI

Use Lean TDD as a set of guardrails for AI-assisted development so test suites stay readable, trustworthy, and focused on outcomes.

What the book covers

Twelve short chapters tracing the path from TDD confusion to a leaner, more useful testing workflow.

Why Lean TDD?

See why TDD gets resistance, why it should not slow teams down, and why Lean TDD aims to remove duplicated effort.

From Waterfall to Agile

Get the historical context for TDD by looking at the problems Agile was reacting to and why feedback speed matters.

Test Driven Development

Revisit original TDD, Red/Green/Refactor, and Canon TDD so the rest of the book builds on the clearest definition.

Why Write Tests?

Frame testing in terms of quality, agility, efficiency, learning, and design rather than habit or dogma.

Lean Software Development

Borrow Lean ideas like value, waste, learning, and flow so TDD practices can be judged by their real payoff.

TDD Interpretations

Compare classical, mockist, and other interpretations of TDD through a Lean lens to see which ideas help and which add drag.

Acceptance Test Driven Development

Look at ATDD as a team workflow for defining done, aligning on behavior, and reducing waste from miscommunication.

Pyramids and Trophies

Evaluate common test-distribution models and how they shape the balance between unit, component, service, and UI tests.

Lean TDD

Put the pieces together into a practical Lean TDD workflow centered on acceptance criteria, behavior, and fast feedback.

Lean TDD for Teams

Scale Lean TDD beyond solo work by adding just enough coordination for developers, testers, and stakeholders.

Lean TDD and AI

Apply the same testing strategy when using coding agents so your tests stay readable, trustworthy, and outcome-focused.

Conclusion

Finish with a concrete next step: start small, apply Lean TDD on real features, and let the test suite grow with you.

Brian Okken

Brian Okken

Software engineer, author, and podcaster

I’ve been writing software professionally since 1996, with a background in electronic test systems and wireless communications. I am the author of Python Testing with pytest and have spent decades practicing, teaching, and refining test-driven development in real production environments.

I have spoken at conferences including PyCon US, PyCascades, and PyBay, and have hosted the podcasts Test & Code, Python Bytes, and Python People.

On occasion, I have taught teams in a corporate setting, helping them adopt practical testing strategies and improve their development workflows. ‘Lean TDD’ is language-agnostic. Even though there’s a lot of Python in my public work, I’ve spent a big chunk of my career writing C++ and other languages in professional settings. ‘Lean TDD’ is about the principles and practices of TDD, not a specific programming language.

Get Lean TDD

Lean TDD is available now on Amazon in Kindle and paperback. If you want a quick preview first, you can also download the sample chapter PDF.

Buy Lean TDD on Amazon Preview Chapter 1 Audiobook coming soon on Audible