I worked at an HR tech startup that did recruiting services for a lot of seed/series A companies. Maximum ages for roles were discussed openly and nobody even considered the possibility doing so might be illegal.
Yeah a coworker of mine looking for a tech job in a different industry had someone straight up tell them they were worried he was too old.... dude wasn't that old. When he mentioned it to the recruiter she didn't even seem to think it was an odd thing to say... so she repeated it.
