Tristan O'Tierney, a 2008 RIT graduate and a co-founder of Square, died last month at the age of 35.

O'Tierney died unexpectedly on Saturday, Feb. 23, in Ocala, Florida, according to his obituary. He worked for Yahoo!, Apple, VMware and Tapulous before co-founding Square, which revolutionized the way people and businesses use smartphones to accept credit card payments.

In September 2018, he shared a tweet about his struggle with addiction but did not go into detail: "As some of you may know, I've been battling with addiction for these past few years. With some success. A lot of failure too though."

In a 2012 interview with the Democrat and Chronicle, O'Tierney spoke about creating Square with Jack Dorsey, who is also the CEO and co-founder of Twitter. They met years before founding Square in 2009, and Dorsey had introduced him to Jim McKelvey, another co-founder of Square.

"(Dorsey) was looking to start a new company and asked if I'd be interested in joining him. Jack then introduced me to his friend Jim McKelvey ... and the three of us began brainstorming ideas," O'Tierney said in 2012. When we first met up, we didn't know we were going to end up starting Square, we just knew we wanted to build something — and it turned out bigger than we ever anticipated."

In the interview, O'Tierney said that his parents, Pamela and Mark Tierney, were in the U.S. Navy and moved around for much of his childhood. He said the only thing that remained the same throughout all those moves was the internet, and that it became his first real home.

Since that 2012 interview, Square has taken off and launched both hardware and software designed to handle mobile payments, point-of-sale transactions and person-to-person payments with products such as the Square Readers, Square Stand, Square Register and the Square Cash app. The company is now valued at around $30 billion, according to the stock market insights site Seeking Alpha.

O'Tierney said in 2012 that he hoped to see the company grow and was always trying to find the best — and fastest — way to take Square to the next level.

"My biggest challenge at Square has always been battling the desire to get just one more thing done in a given day," he said in 2012. "What we're working on is so exciting and our vision is so vast, there is always something more to get done. At a certain point you realize that you're not Superman and you can't change the world in one day. But you can, brick by brick, over time."

GSILVAROLE@Gannett.com

Includes reporting from the Democrat and Chronicle archives.