Ask HN: How to become a ridiculously good back end staff eng?

A bit of a click-baity title, apologies. I'm a senior eng and want to really push myself to better levels. My non-tech skills (comms, collab, leading) are one of my strengths and I'm constantly trying to make them better. I constantly keep feeling that I don't know enough tech stuff, there's a ridiculous amount to learn and foundational blind spots and holes that keep cropping up.

One of the questions I try to ask myself is, if I joined a new team or company, what skills would I need to really help the team succeed quickly and effectively.

A lot of ya'll have been around the block a lot, and either been or worked with such folks. Your insights would be super appreciated