Quick initial reply, good engagement, and then radio silence.
I applied online and got contacted by a recruiter fairly quickly. I had a very engaging and open conversation - it didn't even feel like an interview. We went back and forth via a few emails, then I had a face-to-face interview. I spoke with the recruiter, then with the hiring manager. I thought both discussions went great, and was even told that I would "be asked back for the next steps" by the recruiter.
I followed up immediately with "thank you" emails to the hiring manager and the recruiter, and reiterated my strong interest in the role. I waited for a week...and nothing. No call, no email, etc. So, I sent a follow up email. Nothing. Long story short, I sent weekly follow-ups for 4-5 weeks, and placed one or two calls as well. I can understand that I may not have been a fit, and I can also understand if business objectives pushed off the timing for this role. What I can't understand, though, is the complete lack of follow up either way. I felt left hanging - not something that I think should happen with any candidate at any level.