Growing a company occasionally can require switching gears and letting go of nearly everything you've been doing--even if it's years of work. Anthony Casalena, founder of the website-building-software company Squarespace, ​knows this as well as anyone. The more successful the business becomes, he says, the quicker it will transform into something new and different from what you started as a solo entrepreneur.

When Squarespace started, it was just Casalena programming in his dorm room at the University of Maryland. For three years he built and managed the company himself, even after he had graduated and moved to a tiny New York City apartment in 2006. But eventually, he says in a new Inc. video, it becomes clear that you can only make so much progress on your own.

"I was very comfortable doing a lot of the aspects myself," he tells Inc. editor James Ledbetter. "It just started to get overwhelming. You spend three months working on something and you realize you just spent the month doing accounting, and customer support, and X, Y, and Z, and [you are] not moving this thing forward."

Casalena started hiring people and steadily scaling the company. By 2010, though, he came to a crushing realization: Squarespace was outdated. It had been seven years since the company launched and website technology was advancing past what his software could offer its customers.

"It probably was not going to power the future of websites," Casalena says of the old version of Squarespace. "Browsers had gotten more sophisticated. You had this opportunity to use JavaScript and hardware-accelerated CSS on websites, you could put big, full-screen imagery on websites, and a lot of the people here were really excited about making sites like that."

Casalena decided to do something radical. He scrapped the software he had worked tirelessly to build and rewrote the whole platform. In 2012, the company launched Squarespace 6, a version that could be used to create any kind of website.

Fifteen years into building the now $1.7 billion company, Casalena is now transitioning away from his traditional role. "I've gone from an individual contributor doing all these different things," he says, "to somebody whose main job is dealing with people."