I did an virtual onsite interview with Facebook >2 weeks ago. My recruiter called me today to inform me that Facebook wants to conduct a second interview because one of the interviewers reported that my code failed for a missing edge case. They want to conduct an hour long interview similar to the standard interview where I will be required to solve 2 questions. I believe I did really well in all 5 rounds.

I never heard of follow up interviews. Has anyone faced a similar situation before? Is there something I should be concerned about? Does missing an edge case really have such an impact on the whole interview?

Thanks,