Maciej "MJ" Jedrzejewski – Your AI & Software Consultant in SwitzerlandHomeAbout meMastering Strategic Domain-Driven Design After all the previous steps, we are ready to continue our journey and try to prepare the first draft for splitting the Fitness Studio domain into several subdomains. But there is still a long way to go. First, let’s try to define what a subdomain is. Every business operates in some business domain – we all know that. To keep it efficient, it is usually divided into different a...

Years ago I wanted to start learning Domain-Driven Design. It was quite a popular topic, many of my colleagues were discussing it. The problem, as always, was where to start. I decided to ask one of my old mentors. He told me, “MJ, there is a great book about DDD called the Blue Book. Go and read it and everything will be clear. There is nothing better on the market”. “Well, it m...

Recent years have been marked by microservices. Who among you hasn’t heard of them? They were everywhere – at conferences, groups, job listings, coffee talks, and blog posts. At some point it got to the point where if you weren’t working on a system composed of microservices, it was kind of a problem – you felt the world was getting away from you, and your colleagues were in another galaxy. Someone found a silver bullet for the design of IT systems. On the other...

Recently, I had the pleasure of speaking at 2 programming events – World Engineering Days and one of the biggest software conferences in Poland, 4Developers. During both speeches, I talked about many different things related to the modern way of software development – continuous deployments, short-living branches, canary releases, and more. All are linked to the short feedback cycle. One of the side topics was vertical slices. What is a vertical slice? Before we ...