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.
But what happens if you don’t use an IDE? That was the original point. Even if it isn’t statically typed, a python IDE can also do its best to guess the type of an object.
The point is to have code that’s legible without dependence on large, third party tools.