MongoDB’s dynamic schema is powerful and challenging at the same time. In Java, a common approach is to use a object-document mapper to make the schema explicit in the application layer. Kotlin takes this approach even further by providing additional safety and conciseness. This post shows how the development with MongoDB can benefit from Kotlin and which patterns turned out to be useful in practice. We’ll also cover best practices for coding and schema design.
Code reviews are a powerful mean to improve the code quality, establish best practices and to spread knowledge. However, code reviews can come to nothing or harm the interpersonal relations when they are done wrong. Hence, it’s important to pay attention to the human aspects of code reviews. Code reviews require a certain mindset and phrasing techniques in order to be successful. This post provides both the author and the reviewer with a compass for navigating through a constructive, effective and respectful code review.
I just wanted to convert SVG to PNG files with Python and the library CairoSVG. That was no problem on my Ubuntu system. But running the SVG converter script within a lightweight Alpine Docker container turned out to be problematic. Figuring out which libraries have to be installed up front took me some time. That’s why I like to share my findings here. Hopefully, it’ll save your time.
“Kotlin is great and I really want to use it. But how can I convince my management?” This is the most frequent question I get asked after a talk. In this post, I explain how we introduced Kotlin and show arguments, strategies and tricks that can increase your chances of success. I keep the fingers crossed for you!
The term Microservices is quite vague as it leaves many questions unanswered. Contrarily, a Self-Contained Systems subsumes concrete recommendations and best practices that can guide you to create an application which is resilient and independent. But how can we implement such a system? At Spreadshirt, we build an application following the recommendations of a Self-Contained System. In this post, I’ll show you which technologies we used and which challenges we faced.
Imagine you clone a git repo and try to start its application in your IDE. It fails. Why? The database is missing. After installing and starting a database manually you look at an empty application. There is no data in the database. Moreover, the application still doesn’t work as it requires an external service… The process of setting up a local development environment is often a journey of pain with many manual actions and implicit knowledge. How cool would it be, if we just have to call
docker-compose up and the whole environment is automatically created locally containing nice dummy data?
On April 25, 2018, I held a talk about my favorite topic “Kotlin in Practice” at the JAX Conference in Mainz. I’m still impressed by the huge amount of people that have been interested in my talk (~ 350 folks). There weren’t even enough chairs for everyone. I’m still thrilled! Thank you so much! Also for the great questions during and after the talk.
“Maven is old school” they said. “Use Gradle instead. It’s the future of building Java applications” they said. Sounds like something you don’t want to miss. So I tried Gradle in two real-world projects. In this post, I like to tell you about my experiences with Gradle and why I finally migrated back to Maven. It’s a story about enthusiasm and disillusionment.
On March 13, 2018, I held a talk about “Kotlin in Practice” at the JavaLand Conference. The conference was awesome and 1900 people attended. I guess about 300 folks came to my talk although it was so early in the morning. That was awesome! Thank you so much! Special thanks go out to the guys that approached me after the talk and the kind tweets. I’m still euphoric. :-)
Unit Testing in Kotlin is fun and tricky at the same time. We can benefit a lot from Kotlin’s powerful language features to write readable and concise unit tests. But in order to write idiomatic Kotlin test code in the first place, there is a certain test setup required. This post contains best practices and guidelines to write unit test code in Kotlin that is idiomatic, readable, concise and produces reasonable failure messages.