Peter Cancro was still in high school when he took a leap of faith and took out a six-figure loan to buy a small sandwich shop on the Jersey Shore where he had worked since he was 14.

By the time Cancro joined what was then called Mike’s Subs, the shop, started by Mike Ingravallo in 1956, was already a mainstay of Cancro’s hometown of Point Pleasant, N.J. But Cancro’s vision would later turn the small operation into Jersey Mike’s—a national chain with 4,000 locations open and under development.

As the sub chain approaches a potential blockbuster IPO set to value the company at about $8 billion and bring in at least $1.1 billion in immediate proceeds, here’s a look at how Cancro helped turn a mom-and-pop sandwich shop into a franchise giant.

Cancro, born and raised in Point Pleasant, was a normal teenager with a knack for business from an early age. At only 10 years old, he was mowing lawns for between $3 and $5 a piece and picking up the loose change that fell through the boardwalk along Point Pleasant Beach for some spending money, he said on the Our American Stories radio show and podcast earlier this month.

It was his brother, having worked the year before at Mike’s Subs, who got him a job at the sandwich shop that would later become his life’s work. When he first joined as a 14-year-old in 1971, he started out making $1.75 an hour. Today, his net worth sits at a whopping $4.9 billion, according to Forbes, and should grow after the IPO as he still owns more than 30 million shares in the company, according to Jersey Mike’s S-1 filing with the Securities and Exchange Commission.