The person who for some reason is up on a Saturday night reading the NGINX source code in C to better implement their company's Lets Encrypt integration.
The person who actually stepped through Kelsey Hightower's Kubernetes the Hard way just because they thought Kubernetes was really cool.
The person who writes code for personal projects during "social hours" where others may be out with friends, out with their significant others, etc.
EDIT: I'll leave it for the integrity/honesty of the comment, but here are some descriptors I wish I'd used in the first place instead of 'autism':
* On the spectrum
* Extreme Introvert
* Socially disconnected
* Ties self-value to work-output in extreme ways
* Seeks joy from work versus social interaction & status