Oof, yea I agree, not a great sign for the future. And honestly, that might be a good thing. The biggest issue with this serializer is it’s speed. It starts to show it’s slowness when querying about 100 items, which is not actually impossible to get to for even toy apps build in bootcamps. This summed it up best, from Netflix’s fast_jsonapi comparing their times:

Active Model Serializer serialized 250 records in 138.71 ms
Fast JSON API serialized 250 records in 3.01 ms

I’m going to leave this article up since AMS makes it super easy to learn about serializers as a concept, but I would suggest that users incorporate other serializers in the future.