A couple of scattered thoughts, with a head cold:

The team itself is a design challenge. At the core are people, just like any other design challenge. You can actually get a similar kind of satisfaction working on the design of the humans (the relationships, process, or just helping with their work) as you can from a design artifact, it just takes place over a longer time scale — so you have to be patient. You sometimes get to see your small wins six months later.

At some scale, the day-to-day becomes very different. The more humans there are, the less focus-mode you get by default. One of the most important things you can do is set up and drive the story arc that you want to create. Team goals, team events, people and subgroups you want to help grow, future managers, recruiting, all of that. You have to be building/designing the team, while you're reacting to stuff, so that you're not only reacting to stuff. If you find yourself only reacting to stuff, stop, reset your calendar, and refocus some of your time. Check in on the story arc, and make sure its tracking. What are the themes you want to see happen? Better critique? More focus? More diversity or consistency or communication?

You can pick off small design projects if you are careful and time them well. I look for tiny projects that are interesting but scoped smaller than a full day or two of work, so I know I can commit to designing it and actually deliver. If you need to feel like your tools are sharp and you want to get into the details this is a decent way to do it.

If you have to have a hard conversation with someone, you can practice it first, like you would with a design pitch or presentation. Prep is good.

Stay humble! You're in service to others, now doubly so, as a designer and as a steward of the team. Help out, take care of people, make them stronger and better and you will feel successful.

(Obligatory qualifying footnote: grew design at Palantir from 2-30ish people in the last 3 years. Still feel like I've barely scratched the surface).