I had an internship at this awesome company (a growing startup, ~150 employees) in my junior year of college. It seemed like it went really well; I got along great with everyone, my project went above and beyond expectations, I got glowing reviews during every evaluation, almost everyone in the whole company knew who I was and the work I'd done, the CEO even personally thanked me for my project. I kept in touch with my former coworkers, visited a few times as I worked through my degree, and had multiple people at the company (including my former boss, who still works there) telling me they'd love to have me back after I graduated.
When my graduation date got close, I visited again, this time to talk to the hiring manager (who I had known since my internship) about potential full-time opportunities. I thought that it went well, and they said they'd keep me in mind for future openings, but I never heard back from them again after that (and that was a year ago). I sent 2 more emails, spaced a few months apart, just to touch base again and see if things had changed, but I never got any response. I also sent in an application for a position they had open and still heard nothing back, not even a rejection. (I've done enough job applications to know that that's pretty common, it's just odd combined with everything else.)
I just wish I knew why–were they just not hiring junior devs at those times? Did I mess something up during the process that I wasn't aware of? Did they decide they weren't interested in hiring me after all? I've been hesitant to send them more emails and applications because I don't want to bother them if they've decided not to hire me, but if it was just a bad timing thing I want to keep trying. Would it be a good idea to send another email touching base again (perhaps to a separate contact that isn't the hiring manager, like my old boss)? Or continue to apply for openings I see? Or should I just let the whole thing go since I haven't talked to them in a year?