The Grey Beard
The Grey Beard is the developer that you want to assign features where stability is crucial. This woman, or man, has been in the industry for very long. They have implemented so many systems that they can foresee possible problems from first principles. Disclaimer: Being of old age is not enough to be a Grey Beard.
The Grey Beard is unfazed by trends, and cares only about tried-and-tested technologies, unless there is a very compelling reason. They are willing to change their minds, but they need to be convinced by reason. They can see old concepts in new technologies, and understand its limitations. They know unix tradition systems well, and have sharpened the tools they use through the years.
They exude wisdom, and everybody consults with them, not because of a hierarchy, but because of the extremely good insights they easily provide.
They are humble and approachable, and they are not in favour of abusing extra time, unless a real emergency ― that is, almost never.
UNIX is very simple, it just needs a genius to understand its simplicity. ― Dennis Ritchie
A great Grey Beard, similarly to the Hacker has an extensive knowledge on a multitude of subjects. They can often surprise you with unexpected mastery of seemingly random topics. They can be an almost infinite source of good recommendations.
A good Grey Beard developer has Yoda-level wisdom. They can talk about Emacs, Unix or old systems for hous. But only if you are interested. They are not evangelizing or trying to convince you. They are at peace with their choices. Instead of grumpy and antisocial, they are humble. And their door is always open, provided you put effort and do not expect them to do your work for you.
Cutting through noise
A Grey Beard can cut through buzzword like a Steamroller. Do not try to b*lllsh*t them! They won't be pleased.
To expand your skills
Here are some resources to expand your skills as a .