Odesk and Elance. Only hire people who've worked on multiple projects and have high ratings. There are plenty of talented people out there.
> For the record the Yosemite issues are the most glaring ones.
I commiserate. Apple's arbitrary decisions on what APIs are deprecated in newer versions must be really frustrating for developers. One of many reasons I shy away from creating desktop applications.
I am on Elance, but can't get any work because I don't have any history. Can't get history without any work. The logic in this is flawed. Interview the people who submit bids, don't automatically rule out people without a history on the site, you might be surprised what they've worked on in the past.
If you make an effort to stay on top of all the latest OS releases, life is great, but it's frustrating when you're trying to remain backwards compatible and figure out what the heck is going wrong on the new OS.