The current large tech company I work for had a recruiter posting messages on LinkedIn like “we’re hiring like crazy in <my town> for people with <my background>!” I had already applied on their careers site and got no response. Messaged this recruiter and got no response. Applied again to a similar position maybe 2 months later, got a response, got an interview, and now I’m working there. Guess my point is there’s clearly a lot of randomness in the screening process.