I admit I only dip my toes into the Java ecosystem occasionally. How low is low memory usage? The last microservice-oriented Java framework I used was Spring Boot, but I don’t know that I’d call it lightweight.
Edit: And yes... the folks I was working with were excited at how much lighter-weight Spring Boot was compared to whatever it was they were using before. When I showed them a Go-based server just using net/http, they almost had a stroke!