I was recently contacted by a recruiter. I checked out the company website, and it turns out that I actually know one of their senior staff listed there. He was a fellow grad student at my university (a couple years ahead of me) and briefly collaborated with other people in my research group. We were acquaintances then, and I haven't talked to him since he graduated several years ago.
I did mention this as an aside in the initial call with the recruiter, although I don't think she took note. Regardless, I wouldn't be surprised if it came up during interviews (e.g., "I see on your resume you worked for X doing project Y, did you happen to know Z working on very similar things at the same institution?"). The recruiter thinks I may be a good fit for a more senior role than was initially presented, and is passing my resume to the team for review.
Given that, should I reach out to him personally?
I'm not sure if it would be seen as inappropriate or brown-nosing (since I haven't been in touch for 3-4 years now, and by the time he gets my email the recruiter will have sent on my resume..), but maybe it would be more weird not to say anything? I don't know if he has any particular opinion on my work, although I imagine it is neutral at worst.