How do they know that I actually fit in that department and not in Marketing? Like... I never put who my employee was or my profession..

EDIT: Oh, I did put my profession. Stupid me.

I thought it was implying that if you are the type of person to find that link you could be in the engineering department (ie it isn't dynamic)

we read hacker news :)

If you don't have a facebook account, it assumes you're smart enough to go to engineering.