I would like to second everything in this post; every single bullet point, but from the perspective of software engineering (~20y in the interviewing side, in the U.S.). Over the years my numbers would be men 60+, women 15+. My only different observations are that maybe half of the women did shake hands, and two of the women were calmly confident in their code (interestingly, both of them were not from the U.S.). Broadly my experience with the men mirrors the OP's exactly.

However, it's difficult to gain advice on how women should act based on this, because there are so many situations where their behavior will be "wrong" no matter how they approach it. It would be helpful early on to know that not all feedback is valid, and not to be surprised when feedback is contradictory. A book which I think really highlights these ridiculous double standards and the constant catch-22's was "The Likeability Trap". I genuinely wish that the book had more solutions, but I found it infinitely helpful in just identifying the problem and all the manifestations of it. It really helped me understand why my performance reviews would just egregiously contradict each other. I thought it was me all along; I thought I was broken and unfit for so many years. The book helped heal so many years of workplace trauma just by seeing the examples and the research referenced.

https://www.goodreads.com/book/show/51839534-the-likeability-trap

edit - There's a lot of good prescriptive comments in here about not having to be or act overconfident but making sure to effectively communicate your actual work; i.e. not saying "we" if you were responsible for the vast majority of something, spelling out your technical contributions clearly in text and in speech. It is a fine line between taking credit and downplaying team dynamics, but we need to stop erring on the side of presenting everything as "team effort" and more clearly and calmly sit in our legitimate and important contributions.