From The Jargon File (version 4.4.7, 29 Dec 2003) :
alpha geek
n.
[from animal ethologists' alpha male] The most technically accomplished or
skillful person in some implied context. ?Ask Larry, he's the alpha geek
here.?
From The Free On-line Dictionary of Computing (30 December 2018) :
Alpha Geek
The head geek or geek's geek. When no one else knows
the answer, or several techno-types give conflicting advise,
or the error message says "consult your administrator" and you
*are* the administrator, you ask the Alpha Geek.
(1997-06-25)