On the hiring side, we tried using LinkedIn during a recent hiring round of about 5 highly skilled C developers. We flipped through hundreds of LinkedIn candidates and exactly zero made it past the resume filter. Completely useless. The only successful hiring method we found was actually the monthly Who's Hiring threads here on Hacker News.
Sorry. What I meant by "resume filter" was us manually scanning through the candidates. We put some criteria for C programmers into LinkedIn and got a bunch of web and .NET devs who had also mentioned C someplace. Perhaps skilled C devs just aren't looking for jobs on LinkedIn (totally possible! I wouldn't if I were looking), but I was kind of surprised that we got literally zero viable candidates. I expected at least a couple to look interesting enough to contact.
