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.
I have a hard time believing that rewriting the backend from scratch would be faster than getting PRs approved on the main project.
Forks like this with one guy who “knows best” usually die a slow quiet death as they get left behind by the main project.
I think how quickly this project has gotten to near feature parity is a testament to how slow Lemmy development has been. Think about scaled sort (a feature that has been hotly requested since the migration) and how long that took to get merged in. A sort should not by any means be slow to implement.