Spring Boot is a handy way to create pre-packaged web applications with a built-in server. A good example of this was that once upon a time VMWare had a desktop management console app that was written as a webapp. They had to package up their very own private copy of Tomcat along with their management app code and make it all easy enough to install and operate that the average drooling VM operator wouldn't have to even know that they were dealing with Java. Alas for them, Spring Boot was still several years in the future, but they did a decent job of it, regardless.
These days many times it's useful to have a single-app webserver. They lend themselves well to containerization, for example. But of course, they're not the solution for everything. Sometimes you may find it better to host multiple applications in a single appserver, old-style. Sometimes you want something whose insides are more accessible for advanced custom configuration.
Where you get your experience from is less important than what you can demonstrate having done with it. In that sense, publishing open-source projects is actually better, since as a rule, it would be a problem for me to display applications from a former employer to a potential new employer.
"privilege" comes from the Latin words for "private" and "law" (legal) and dates to feudal times. To "claim privilege" meant that you were above the laws that applied to the common people.
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