the algorithms used for analysing social media presence etc of potential employees for tech companies are completely skewed towards stereotypical requirements (like an interest in anime etc)
Because watching cartoons somehow improves your programming skills. What the actual fuck? That's not about hiring the best programmers AT ALL, that's about hiring people who like what you like and share your values about the appropriateness of tentacle porn so that you never have to face criticism for your porn habit and the way you treat your girlfriend at the office.
I think that sadly the attitudes you describe to women managers or would be managers are not restricted to women that dont know how to code.
Well, yes. Women in Silicon Valley have to be shit-hot at their jobs, way more than men, to get half the level of respect. And even, that respect will evaporate and be replaced with unmitigated misogyny the second she complains about booth babes or the strippers at the office party. Basically, be (or pretend to be) the "cool girl" who is a-ok with male sexual entitlement flaunted right in her face, or face censure. It's only less overtly awful in the UK because we have laws to stop the worst of it.