Probably a custom PostgreSQL extension for BSON support. The biggest issue right now is that MongoDB compares and sorts values differently than PostgreSQL/json

Probably a custom PostgreSQL extension for BSON support. The biggest issue right now is that MongoDB compares and sorts values differently than PostgreSQL/jsonb. For that reason, we have to do a lot of filtering on the FerretDB side, and that can't be great for performance. Pushing more work on the database size should make FerretDB perform much better.