Freelance software consultant Maciej Walkowiak (of Just and Spring Cloud AWS fame) has recently published this interesting article on dynamic projections with Spring Data JPA.
Dynamic projections allow you to determine the type returned by JPA query methods at invocation time, which comes in handy in case you want to return different attribute subsets from your data model for various use cases without having to incur the maintenance cost of creating a new query method for each such projection.