Additional and/or complex examples for elm-codec?

Does anyone have some examples of building complicated encoders/decoders with elm-codec? I’m trying to build something fairly complicated and I’m missing reference examples for things like using map and andThen and combining codecs and stuff.

You can find examples for map and andThen functions in the Codecs module of Em Designer here: https://github.com/passiomatic/elm-designer/blob/master/src/Codecs.elm

I have an example using map, constant and set here and a codec for a recursively defined custom type, which is pretty gnarly!