I got an email asking if I was interested in a better role and after replying back yes I got a calendar invite today asking me to attend an Ask Me Anything (AMA) session (in like 10 hours) by the founder where I and other people he was talking to will get a chance to talk to him about his passion and ask any questions we had. I found it a bit strange and politely said I couldn't attend it. After the event he emailed back saying the event went well and asked me why I couldn't make it. I honestly told him I find it a bit strange to do an AMA before an interview. Is it normal to do an AMA (with many potential candidates at once before an interview)?
It is strange BUT he offered an opportunity for exposure in a high value setting. By declining you are implying that you aren't interested in why the founder is passionate about the organization or the direction they see it going.
If you are trying to impress someone and they invite you to listen to something they are passionate about usually it's a decent idea to hear them out.
It is not very common but at the same time not very strange. They might be aiming to give candidates as much information as possible and using the session as an informal group interview to gauge candidate interest and also allow candidates feeling uncomfortable with the culture, work etc. to drop out before going through all the following steps.
In your case I would say it worked. You did not attend because doing an AMA before interview was unconventional which made you uncomfortable. Their culture likely promotes innovative thinking with a lot of unconventional approaches. So culture mismatch, avoided.
I'd consider it part of the interview process. There's always dumb things you have to do, and things that look dumb that you have to do. Think of this as one of them, if it helps. So, you blew off an interview session, and you demonstrated that you really aren't interested in how the company got to be the way it is. That's probably enough for you to be dropped as a candidate. Let it be a lesson for the future.
My company does this as well, but in a different way. We have a formal and informal interview. The formal interview revolves around skills, experience and ability. The informal interview is to determine if the candidate "meshes" well with the team, it's structured very much like an AMA in that you can ask almost anything.
I cannot speak for the AMA you skipped, but the reason we do it is to break the ice with a new candidate. Let them get a sense of the the people they're working with and let's us know what the candidate is comfortable with. It can be an intimidating process, however, it's one of the best ways to really get a sense of a candidate. To see if they can have a voice in a group of people.
Because developers tend to wear many hats at our company, we need our candidates to be comfortable with the idea of talking to people who are and aren't technical. (Our open session has one Technical Lead, One Support Agent and one Junior Developer) We also need candidates who can communicate. Since communication is vital to a small team, it's key to find out if the candidate has those skills.
I've never been asked this in a one to many setting, sure there's discussions about non work things and a getting to know portion of most interview processes, but the one to many nature and timing of this makes me think it's for selling vacuums door to door instead of something legitimate. Most CEOs I've met have better things to do than talk to random folks who may or may not join for almost any reason, if they join the interview process it's usually towards the end.