I understand that you have no control over who you're interviewing with but... if you're a good fit and the interviewer leaves thinking you're a terrible fit that's a sign of a bad interviewer. Obviously there are non-proficiency things you can do to skew that perception (bad hygiene, late, obviously disinterested) but a good interviewer (especially one used to working with developers) should be good at getting by all the social awkwardness to evaluate your problem solving.

And yes, most large companies have terrible interviewers.