In a senior role, you'll spend more time working with people who aren't developers. PMs, designers, managers, etc. In your first few weeks, book a little bit of time to meet them. They'll appreciate the forwardness, you'll quickly expand your network in the company, and it can be the start of a good working relationship that pays off 3-6 months later.
Yeah this is the biggest difference imo. You have to play the game at the senior+ level, that means no more just doing tasks and then sitting back. You have to reach out to people and schedule meeting, you have to be speak up during team meetings, you have to do tech talks and demos.
Upper management has no idea what anyone is doing, they will make layoff/promotion decisions that seem insane from the ground floor, so make yourself visible. I legit am still at my current role because of one demo I did that caught the CTOs eye. I was demoing something that took me maybe ~2 days and was relatively minor in my teammates eyes, but it got my name on his radar so I made the cut.
