Meta Software Engineering Manager interview questions

A recruiter reached out on LinkedIn and set up an interview, after the initial typical screening. After that a phone call was set up, which was then rescheduled. Facebook provides an awesome question guide (as does Google/etc.) so you know what to expect - plus all of the questions for the Engineering Manager role are straightforward and if you have experience doing the job, should not be a problem. My first question was about the hardest time I had firing someone, and in my case it was a non-technical (sales) employee, which the interviewer seemed highly put off with. He said he has never managed a sales person so he's not sure what sales goals are. When I attempted to explain and/or move on to a story of letting an engineer go, he moved on. The next question was about architecting a scalable solution and the process. I probably made a mistake here going for a little bit older solution, however I personally felt it highly relevant to the interview as it involved building a product on Facebook that Facebook now provides, designed for maximum scalability. (Though within the time constraints we had.) The interviewer seemed clearly put off by the time period, asked for a bit of clarification about what we would have done next to continue the scalability, and moved on. My gut feeling was he was not impressed with the answer, however in the context of the question you must also consider the fact that we were a small start-up under considerable time and money constraints, so the solution was based on what we had time for and could iterate on in the future if the product took off. When it came time for me to ask questions, I asked if the interviewer had any recommendations for continuing to pursue the role if I was not selected at this time, and his recommendation was to obtain the same job at a huge company that was like Facebook but not. The interviewer was 10 minutes late in joining the interview and said we would be moving the first portion of the interview to the end, but ended up skipping it altogether. My impression was throughout the interview that he would not be making a recommendation to move forward. Personally, as someone who has trained with both Facebook and Google's anti-bias resources I felt that the interview was highly subjective and biased, and likely weeded out a candidate who would have been a perfect fit at Facebook.