I'm thinking that this would only work for relatively simple apps though. There might be cases where the functionalities in your apps could only be supported by server-side infrastructure, like uploading files, resizing images, emailing, cron jobs, etc.

What would be really nice is if Parse had a way to somehow plug in existing backend infrastructure to Parse's data model.

Edit : I take it back. Parse has a REST API.

You can use their REST API. It's really well made and I've done a few smallish projects using it.

Annnd you just said that. Didn't see your edit heh.