Penetration testing now. That's what I wanted to do as a high schooler more than 15 years ago.
Started as C/UNIX dev, but as a way to find a "first job" because I needed $$. I did this for around 3 years.
[ my public key: https://keybase.io/meik; my proof: https://keybase.io/meik/sigs/P8fhyNYyRz0iHnACel7AlPq77Q97GiQa_D5aey8dLWo ]