Original link: I Rewrote Our Python API in Java. It Got 15x Faster (And 3x More Annoying) / CodexLab.
Same old story.
Developers do not like Java and Spring Boot at all.
But for high volume complex business logic then they just work.
Note that as usual when people write Spring Boot then it is really more Spring MVC and Spring DI. Technically Spring Boot is just the framework for embedding the servlet engine (web server) while Spring MVC is the web application and web service framework and Spring DI is what is used to glue it all together.
But nice touch using Spring Batch. It is actually a powerful library for data processing.