React TDD 3: Dependency Injection


Why doesn’t React come with dependency injection? Short answer: Because it doesn’t need it and also because it is not its responsibility.

But how do you isolate your components during testing then? How do you achieve inversion of control for dependencies when you do not have a dependency injection container?

Let’s have a look…


Our Employees Should Learn on their Own!


Some years ago I was talking to the technical lead of a medium-sized company. I told them that I had just taught a 2-day training about the new features of Java 8 to two teams at a very large company.

He said: “I will never understand why those large companies spend money on training something like that. Like, language features! I expect my employees to learn those on their own, out of curiosity!”

Two people sitting in front of a computer, studying


React TDD 2: Value and Cost of Tests


When test-driving a UI, should I test whether the text of the start button is “Start”? What about the CSS class or style of the button? It’s disabled state?

Of all the possible tests I could write, which are the ones that bring value? Which ones would get in my way later if I wrote them?


React TDD Part 1: Testing the UI Itself


Can you test-drive the UI of a web application? And why would you even want to?

With React and some extra tools, testing at least some aspects of the UI is easy. Let’s take a look…


React TDD Part 0: All Posts


Can you do test-driven development with React? Can you test-drive the UI itself? And why would you even want to?

With React and some extra tools, testing at least some aspects of the UI is easy. In this video series, I’ll show you how.


Brain Based Training


Earlier this autumn, I attended the “Training from the Back of the Room (TBR) Certified Practitioner” training and then I also became a certified trainer for TBR. After the “certifed course”, to be allowed to run “TBR Certified Practitioner” trainings, we had to complete some writing assignments.

My first assignment was:

A fellow trainer who is a colleague and friend of yours has asked for your help in designing and delivering a new course. But your friend has no idea how to use brain-based training design and delivery strategies. How would you help your friend get started? What information would you consider crucial for your friend's success and how would you explain this information to him/her?

And here is what I wrote…


3X Thinking Part 1: eXplore, eXpand eXtract


I spoke about “3X thinking” with Antony Marcano. 3X was originally coined by Kent Beck and it describes the “profile of a winning idea”. 3X thinking will help you to determine whether it’s best to experiment, scale or operate for any given idea.

In this first video, Antony and I talk about the basics: What is 3X thinking and how can it help you as a developer, manager or C-level executive?

Read the whole transcript below the video.


3X Thinking - All Posts


How does an idea become a winning idea?

In Summer 2019, I interviewed Antony Marcano about “3X Thinking”, and this led me to “explore” (ha!) a bit more. Here, I want to collect the interviews with Antony any my own thoughts and ideas about the topic.

Read / watch all parts of “#3Xthinking” here:


Tim Bourguignon: Podcast Developer's Journey


Tim tells me about his podcast “Developer’s Journey”. There, he interviews software developers about their career, what is important to them, and more.


Simon Harrer: Document by Examples


I interviewed Simon Harrer at Developer Week 2019 in Nürnberg, where we talked about his book “Java by Comparison”. With this book, you will learn how to write clean and maintainable code in object-oriented languages.