Left Google about a year and a half ago; leaving at 4pm is pretty unusual from the folks I worked with, though I had a couple of team members who would have 'pick up kids from school' blocked out on their calendar, and taking a longish break midday or in the afternoon was totally fine if you didn't have any meetings. Most people I know tended to come in to get the tail end of breakfast, so 9/9:30, and often stay for dinner (6:30). I had a colleague who did 6am-4pm or so to avoid traffic, though, and another who wouldn't come in until about 4pm for the same reason.
It's difficult to work with folks with 'unconventional' schedules if they are involved in cross-functional or managerial stuff. Fine if you're an individual contributor, but if you need to get a few folks in a room together frequently (project leads, etc) and their working hours have zero overlap, someone's going to get grumpy. I appreciate flexibility in schedule, don't get me wrong, but I also appreciate a bit of self-awareness :)
Yeah, you basically end up treating them that way, but with a low-level amount of annoyance since they should be more available during standard hours. Depending on the person and the role, it can be ok to deal with though -- I'm not totally against the idea of working whenever is most convenient for you, it's just caused me personal frustration when trying to PM a team with multiple folks with differing offbeat schedules.
It's difficult to work with folks with 'unconventional' schedules if they are involved in cross-functional or managerial stuff. Fine if you're an individual contributor, but if you need to get a few folks in a room together frequently (project leads, etc) and their working hours have zero overlap, someone's going to get grumpy. I appreciate flexibility in schedule, don't get me wrong, but I also appreciate a bit of self-awareness :)