Sure, my complaints are mostly around error handling. My comments might not be accurate since its off the top of my head. When a field raises an error I've not

Sure, my complaints are mostly around error handling. My comments might not be accurate since its off the top of my head. When a field raises an error I've noticed the value gets replaced with a "None" type (or maybe its removed from the passed data object) when using @validates_schema. This is annoying because I have to pass the original data and see if the value is actually null or not. This can suck when using JSONAPI because you have to be super careful with your data extraction (eg. data.get('data', {}).get('relationships', {})...etc). I would like more control over how validation is executed. The ordering of validation, the ability to stop validation or continue validation at arbitrary points. Maybe in my validator I could do something like "raise ValidationError(msg, stop_validation=True). I would like more control over pre and post dump/load order. Sort of like a z-index in css. So when using marshmallow-jsonapi, I can specify pre_loads that access the data before and after the jsonapi pre_load formatting. I would like a better way of using "class Meta". Right now its annoying to inherit from a base then define additional "class Meta". I think I ended up subclassing SchemaOpts and settings my defaults that way on my base schema. I would like a way to replace error messages so instead of "Missing data for required field", it would say "Please specify data" (or whatever). I want to define this at the schema level too. I don't want to have to constantly define fields with the same behavior everywhere. It would be cool if Marshmallow had a dictionary of error codes and messages. So it would look like {'1': 'Missing data for required field.'} and I could override that error with "errors['1'] = msg". If I had to sum it up. I like to write small functions and classes that have limited uses. A lot of times I feel like Marshmallow pushes me into more monolithic work so I can control the flow.