It's because of the time constraints required in an interview. At my job, the assumption is that you won't have enough context and experience to be effective in the job until you've been there for 6 months. You can't fit 6 months of prep into an interview.
Good interview questions are ones that boil that 6mo+ of experience down to something that can be explained in 5 minutes and solved in 45. Ideally you'd just work for the company for a few months and then they have their signal, and that's how internships and contractor conversions work. Most people with experience are unwilling to quit a job for a 3-month trial period though.
I've long thought that it might be interesting for an interview model to emerge where a trial period of weeks/months is the expectation. I think this might resolve much of the current frustration with programming inteviews. But I also recognize that doing so would be significantly different from how essentially all other companies operate, and if it weren't communicated clearly enough, could result in negative PR for a firm trying such an approach.
He interviewed as an engineering manager, his job will be probably people management, hiring and moving tickets around. Do engineering managers in meta do any technical work in order to require lc mindset? What 6 month experience do you expect from an new joiner engineering manager other that attending meetings and get to know the projects in high level and what do you expect to see in these interviews through lc questions?
This. Also, 3 month trial periods instead of interviews are not going to happen for two reasons: a) there are still many people out there applying for jobs that couldn't code an append operation for a linked list, b) the cost that such trials would put on companies - if you ever mentored a junior you know the cost. It's worth it, but only because >90% of the recruits are valuable afterwards.
Good interview questions are ones that boil that 6mo+ of experience down to something that can be explained in 5 minutes and solved in 45. Ideally you'd just work for the company for a few months and then they have their signal, and that's how internships and contractor conversions work. Most people with experience are unwilling to quit a job for a 3-month trial period though.