How long should I wait to follow up after a second interview?

I’ve had two job interviews for a job at the local office of a national company. The first interview was with an executive from the national headquarters in another city; the second was with that same person and the manager of the local office. Both interviews were via MS Teams.
It’s been a week, and I haven’t heard anything. When should I send a follow up email, and which person should I email? One or both?

Just going by what I’ve seen on the workplace side, a week seems like the perfect time. They’ll have had time to interview other candidates, and if yours was an early interview, a friendly email now will get you fresh in their minds.

Make it a thank you email to both. That will remind them and might guilt them into responding. I don’t know about now, but ghosting candidates - even after second interviews - seemed to be a thing.
Did an HR person say anything about when you should hear?
It’s always been the case that the time flow is very different for the interviewer and the interviewee.

Agreed, and I wouldn’t wait much longer than a week. I don’t think a week is at all too soon, but waiting any longer could be too long.

I sent the email yesterday. Now let’s see if I hear back or if I’m being ghosted.

Yeah a week is my rule of thumb. I polite “thanks, just following up, excited to hear next steps” will never do any harm.

And in my experience at that point in the process its more likely to be that stuff got held up (senior manager went on vacation, etc.) but its still in play, than a hard no but they’ve not told you yet (and either way sending a follow up email won’t make one or the other more likely)

Another reason to send a thank you - in some areas, the strong job market lets candidates ghost employers (as opposed to the other way around, which is standard.) Sending a thank you makes it less likely you will, and could help.