It’s what we call a "pen test," short for "penetration test," and it’s a large part of what my life consists of these days. I have hacked into some of the largest companies on the planet and penetrated the most resilient computer systems ever developed—hired by the companies themselves, to help them close the gaps and improve their security so they don’t become the next hacking victim. I’m largely self-taught and have spent years studying methods, tactics, and strategies used to circumvent computer security, and to learn more about how computer systems and telecommunication systems work.