The problem I have is: build a scalable backend API decoupled as much as possible from the frontend. And more in general, to build a Web application using some kind of frontend. I would like to compare mainly Liferay with Spring Boot
The most important factors for me are: scalable backend, API documentation, TDD, integration with frontend application for modern reactive interaction
It's a general development question, be more specific, because /dev/std... is a generic approach, not a targeted development. You want to develop PHP or Java? Both are good in their terms, but it's your decision. For PHP Laravel is a robust and exhaustive console enabled framework, featuring rich integrations with virtualization & REST. On the other hand, Spring will bring you learning curve if you are switching from PHP and so on. Try to match your needs with project requirements, it will be easier.
Laravel is lighter weight. Spring Boot quickly becomes a handful, as you'll be downloading hundreds of megabytes in dependencies for a few functions and a dynamic dependency there. There are multiple problems that are solved by "download and put it on your classpath by whatever means. Spring framework will automatically detect it and resolve the issue". It's magical when things work, but my teams have constantly found the limits of the framework's utility and starting points of their burden.
While my expertise with Laravel is more limited, I haven't seen this kind of mess in that community and God bless 'em for it.