Need to write microservice on Java? The first thing that comes to mind is to take Spring Boot, to write quickly several lines — and then off to production! And nobody ever thinks that there is even more easy and, more importantly, standardized alternative, based on Java (Jakarta) EE. To make it possible, several vendors of EE servers have come together and developed a very lightweight specification, designed precisely for microservices. Implementations of this specification, made by different companies, can work on various hardware from Raspberry Pi to large clusters. This specification proved successful and continues to evolve, offering new very useful features right out of the box.