As you can see on my LinkedIn, I had some prior experience with building a new division: https://www.linkedin.com/in/pawel-huryn/

If I were to start again, I wouldn't quit my job but maybe limit it to 3 days / week.

Selling developer's time for a small team is easy, because there are always less good developers (supply) than needs (demand). One of the easiest scenarios is to become subcontractor of other IT companies and gradually look for your own customers. You can do it immediatelly.

The most challenging for me was:

- Financial liquidity. Projects can take months and some customers won't pay on time. If you have employees, this can become a real problem. I learned to work exclusively in Time & Material or to deliver anyting more than a demo license only after the invoice is paid

- building a business that can function without you. You need to learn how to create other leaders.