The DoD obviously contracts with tech companies. Historically, I gather, there was lots of ~blind patriotism. For maybe 20 years, the NSA was officially "No Such Agency". That's far less so now, clearly.

Regarding talent, the CIA and NSA clearly recruit in academia. However, I've read that the NSA also draws heavily on enlisted personnel, and trains them in house. Also, I've read that it recruits from the non-white-hat hacker community. But maybe that's dated information.