Problem

Earlier our serializers were written in a way to support Hit as well as subclasses of AbstractMedia depending on whether they were serializing results from the ES or the API database respectively.

Later we decided to

• slim down the ES indices
• make 1 call to the API DB per request to map Hits to models
• always serialize models, never Hits

These changes did not remove all edge-case handling that were incorporated into the API for fields that were not present in Hits.

Occurrences

Collect occurrences of such handling here. The issue can be considered resolved when all of these occurrences are resolved.

// 🚧 TODO

Additional context

An example of this handling being removed is #4027.