Well, if you have solid technical experience, but are being very nervous and quiet, and a recruiter tells you straight to face that "culture fit is more importa

Well, if you have solid technical experience, but are being very nervous and quiet, and a recruiter tells you straight to face that "culture fit is more important", then the reason for failing 30/30 interviews seems fairly clear. Why don't you A/B test yourself? Take double dose of your favorite anxiolytic and dress more casually to next interview and see what happens. If you fail again then it's 31/31 and not a big loss.