O’Tierney was open about his ongoing struggles with addiction.
Tristan O’Tierney, who co-founded the payment company Square, died on February 23 in a hospital in Florida.
No official cause of death was released at the time of the announcement, though his mother, Pamela Tierney, told the San Francisco Chronicle that it “was in relation to his addiction.” Tierney, a software engineer who developed Square’s original mobile payment app in 2009, had been in a three-month rehabilitation program in Ocala, Florida, and had previously discussed his struggles with unspecified dependency issues on social media.
A graduate of the Rochester Institute of Technology, O’Tierney began working in Bay Area software companies like Apple and VMWare in 2005 before joining forces with Twitter co-founder Jack Dorsey and Jim McKelvey in 2009 to co-found Square, which allows individuals to accept credit card payments on their smartphone or tablet computer. O’Tierney, who created the company’s original mobile payment app from Dorsey’s napkin sketches, remained with Square until 2013.
The company issued a statement in regard to O’Tierney’s passing that read, “Tristan was a part of Square’s founding story and we are deeply saddened by his passing. Our thoughts are with his family and friends.”
After leaving Square, O’Tierney turned to photography, which he described as his “singular creative outlet.” His website showcased examples of his landscape images and portraits, taken at locations throughout the world.
O’Tierney addressed his struggles with dependency via social media. In 2018, he wrote, “As some of you know, I’ve been battling with addiction for these past few years. With some success. A lot of failure too though (sic).”
Tierney’s mother said that she had recently visited her son at the Ocala rehab facility, and reported that he was doing well. “We had a great time,” she said. “We just kept hoping and hoping.”
Pamela Tierney said to the Chronicle that at the time of his death, a doctor informed her that O’Tierney had experienced kidney failure and was in cardiac arrest. “I know he got to the hospital, he couldn’t breathe, and they couldn’t revive him,” she said.
Friends and former Square colleagues posted tributes to O’Tierney on their own social media accounts. Dom Sagolla, a former associate and roommate of O’Tierney, told the Chronicle that he wanted “his memory and legacy to last.”
In addition to his parents, O’Tierney is survived by his parents, daughter, Rumi Ari O’Tierney, his half-sister, Terri, and girlfriend Anjela Ramos. A memorial is scheduled for March 2 at Brookside Funeral Home in Houston, Texas.