John Allspaw at Etsy has a great list of personal characteristics he sees in senior engineers:
In order not to confuse titles with expectations that are fuzzy, sometimes I’ll refer to engineering maturity.
Meaning: I expect a “senior” engineer to be a mature engineer.
I’m going to gloss over the part where one could simply list the technical areas in which a mature engineer should have some level of mastery or understanding (such as “Networking”, “Filesystems”, “Algorithms”, etc.) and instead highlight the personal characteristics that in my mind give me indication that someone can influence an organization or a business positively in the domain of engineering.
Everything on the list rings true to me. Especially the bit about senior people lifting those who work around them.