I know of departments in some of the investment banks that are essentially CS R&D. There are some hedge funds (HFT and otherwise) that are basically playgrounds

I know of departments in some of the investment banks that are essentially CS R&D. There are some hedge funds (HFT and otherwise) that are basically playgrounds for PhD. Of course, in both cases, your work is ultimately directed by revenue, the shield I'm talking about is more against the tight, client/user responsive iterative process of most modern software development which can make it difficult to carve out the time and space to work on something deeper. Also, I'm not convinced academia is much of a panacea here: I hear there is a nontrivial number of years of pretty severe drudgery before you arrive in the sort of position with a lot of freedom to work on whatever you like.