Most of my red flags are just bad interview practices. Not following up with me for months after an interview, holding 8 person panel interviews.
My biggest red flag is if the direct manager and I don't get along. This is the person who is going to make or break your team and if they are flaky or angry or incompetent, it's most likely the team who will get thrown under the bus.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.