yes. back in the day i would tend to wrap my database api in xml first in a standardised way and then i could just use xslt to return json or other formats from the api depending on the mime types requested by client. this fits in nicely with fielding's REST principles. all those technologies (HTTP/REST, XML, XPath, XML Schema, XSLT) actually work very nicely together and allow you to build nice systems that are very flexible, easy to integrate with and easy to change, even though they can be hard to make fast. maybe "move fast, break things" was a bad idea? =)