Seems like an interesting effort. A developer is building an alternative Java-based backend to Lemmy’s Rust-based one, with the goal of building in a handful of different features. The dev is looking at using this compatibility to migrate their instance over to the new platform, while allowing the community to use their apps of choice.
Modern Java isn’t that bad, and with new developments like the graalvm and cloud native builds, or what they are called, the footprint of a modern Java app can be comparable to an golang app.
Modern Java kinda has the same image problem as modern PHP. Not saying is all great, but it sure has seen quite the improvements in the last years