Django API Forms
Just found a really cool library for using Django's built-in forms to validate JSON: https://github.com/Sibyx/django_api_formsI made a small example with it to show how it works with ModelChoiceFields: https://github.com/pawl/django_api_forms_modelchoicefield_example
Seems like a more lightweight version of DRF's serializers (but only for deserializing and validating) and with a similar API to Django's built-in forms.