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SMEs, Steer Clear of Microservices!

April 15, 2024

Latest Posts

Performance June 12, 2023

Goodbye Performance Issues: How Project Loom Eliminates Asynchrony

Anyone who develops a backend application with more than a handful of users knows that most performance problems are related to I/O. In modern web applications, these are typically network calls. Whether it’s REST requests to another service, queries to an external database, or communication with middleware. We handle all these cases - consciously or unconsciously - in asynchronous threads. This way, we no longer block the main thread. Doing this correctly is not trivial.

Marcus Held

JPA January 21, 2023

Accessing Non-Final Property Name in Constructor With JPA

The implications of JPA always manage to surprise me. Yesterday a colleague of mine made me aware of a warning in IntelliJ. The conversation went like that: “Marcus, in your blog you explained that we should check constraints in the constructor instead of bean validation . Me: “yeah”. “I wanted to make it right, but when I do it in this entity IntelliJ warns me with Accessing non-final property name in constructor”.

Marcus Held

Clean Code November 20, 2022

Don't confuse configuration and constants

From time to time I experience that an application is unnecessarily configurable. In a recent project I experienced how too many options lead me to feel much more complexity and increased my mental load. Looking deeper into some of the values I saw that these were actually constants that would be dangerous to change “on-the-fly” anyway. In this post I reflect on this and share my thoughts. In this project the backend processes data from an embedded devices that communicate through LPWA networks.

Marcus Held

Architecture July 28, 2022

Microservices are a Big Ball of Mud

Over the past years I attended hundreds of interviews. Many candidates proudly told tales on how they develop their projects with a microservice architecture. Often (I don’t want to say “always”, but from my memory I think it actually is “always”) it does not require many questions to see that they used a rocket launcher to kill a mouse. Microservices are hard. Everyone who experienced the pain of operating such an architecture can relate to it.

Marcus Held

Clean Code March 20, 2022

Java Bean Validation is an Anti-Pattern

The javax.validation package is widely used in our industry. And I don’t like it. I believe using bean validation is an anti-pattern. It hides business relevant constraints, it leaves the choice when a validation happens to other framework code, and I even saw cases where developers expected that the validation “just had to take place”, but it never happened. Of course, there was also no test for it. And speaking about tests - testing these business relevant constraints is painful as well.

Marcus Held