COOL FOR: MACHINISTS. TINKERERS. INSTRUMENT PLAYERS.
Interfacing wants you to connect to machines: to use and improve them, because that makes you a better human organism. It enables you to understand interactions with machines — be that how to repair the motor of a Kineema motor carriage, how to analyze the way a suspect used a pen, or how to re-figure electrical circuits. It even lets you steal keys off a keyring without being noticed.
At high levels, Interfacing will isolate you from society — why bother with people when you can talk to machines? And why bother with things like money when you can just pocket that display sandwich? At low levels, however, you will have a crucial part of the world cut off from you. People use machines to commit crimes all the time — if you can't understand how a crime was accomplished, how can you solve it?