@robyoung I think our eventual goal should be to add n-level grouping but at the moment it feels like a nice to have rather than a must have. That being said if you can get it working and keep all the tests passing for very little effort then of course go for it. 

I also think that there are two types of formatting.

- domain-ish stuff like expanding `_week_start_at` into `_start_at` and `_end_at`
- lower level formatting that makes the database responses sensible / workable