Being an impressive candidate is achievable in many ways, but one way to impress and stand out is to teach something to your interviewer. Perhaps it's a niche technique, an obscure library function or a neat CSS trick. Either way, be casual and just take a moment to point it out and see if they knew it. Interviews are just conversations, and one of the tenants of a great conversation is that both people benefit. So keep that in mind for your next interview.
Heads up: As with any terse bit of advice, there will be exceptions of course, and subtleties and nuance that can't possibly be captured in a Byte of Wisdom. This has been what I've experienced, I'd love to hear yours in the comments too!
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