That's exactly what I'm going/trying to do. I have around 12 years of experience as backend dev (PHP, SQL, queues, rest apis, e-commerce, docker - so basically whatever needed in the given company). I tried to apply for a Java (Spring Boot) position, but so far doesn't work. I sent few CVs already, but an answer is always no because of "lack of commercial experience". Although I say know Java 8 a bit, and basics of Spring Framework. And also being ok to have 30% salary cut.