TIL that json/add/core exists and provides JSON serialization for Ruby core types (Date, Time, Symbol, etc).

My mantra of "native JSON types only" was entirely because I did not want to add custom serialization code to Sidekiq. With these extensions that mantra remains true but greatly improves the developer experience for all Sidekiq users.

Since the serialized job arguments can change before vs after, this issue may cause subtle compatibility issues. We need to be careful here.