I was the CTO at WhisperSystems, which was just acquired by Twitter. In the past, I’ve done both contract and full-time software engineering work, and I’ve worked on boats and as a delivery captain. I’ve also spent a considerable amount of time being broke and living without money.
I don’t think I have any particularly sage advice for software engineers looking to go independent, so I’ll answer a different question: on a somewhat regular basis now, I receive inquiries from young people coming out of high-school or college, asking me what they should do to get started in their software or security career.