Tristan O. Tierney, a Square co-founder who created the company's first mobile app, died at the age of 35 from causes likely related to addiction


Tristan O'Tierney, co-founder of Square Payment Company in San Francisco, died in Ocala, Florida, on February 23, from addiction-related causes, his family said. He was 35 years old.

He is survived by his 3-year-old daughter, Rumi Ari; his girlfriend, Anjela Ramos; parents, Mark and Pamela Tierney; and his sister, Terri Lynn Cloud.

His family is waiting for an official cause of the death of the officials.

"I know it was related to her addiction," said Pamela Tierney. "I know that he arrived at the hospital, he could not breathe and they could not revive him."

O'Tierney was taking part in a three-month rehabilitation program in Ocala and had been battling drug addiction for three years, Tierney said. O & # 39; Tierney openly discussed his struggles with addiction on social media. "As some of you may know, I've been dealing with addiction for a few years," he wrote in September in an Instagram post, now deleted, that he also shared on Twitter. "With a little success. Many failures too. "

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Born on a naval base in Adak, Alaska, O'Tierney grew up in various states before moving to New York. He attended the Rochester Institute of Technology from 2001 to 2008 and earned a degree in Computer Science. He first arrived in the San Francisco Bay Area in 2005, when he was a software engineer at Yahoo. He then held positions at Apple, VMware and Tapulous.

Jack Dorsey and Jim McKelvey hired O'Tierney to develop Square's original mobile payment app in early 2009, and O'Tierney is generally credited as co-founder. He left the company in 2013. Square, which now has nearly 2,000 employees, declined to comment. The company's website does not mention O'Tierney.

"I will really miss him and want his memory and legacy to last," said Dom Sagolla, a former partner of O 'O Tierney who was also briefly his roommate. O'Tierney also helped develop the official iPhone application for Barack Obama's 2008 presidential campaign. Sagolla, who worked with Dorsey in a podcasting software company, Odeo, which gave birth to Twitter, said that he had introduced Dorsey and O'Tierney in 2008 at an event on the development of iPhone apps he had organized.

A 2014 Business Insider article stated that Dorsey had initially hired O'Tierney to work on a different project called Log, a private logbook application, before turning to Square, who originally called Squirrel.

Many Square colleagues shared O'Tierney's memories on Twitter after learning of his death.

Saddened to learn @TristanPass over the weekend. I still remember having built the first Square app together all these years. He was always excited to build something new. Thanks for everything, Tristan. I'll raise a glass of whiskey for you.

– Robert Andersen (@rsa) February 27, 2019

Pamela Tierney said that she had visited her son in rehab two months ago. The two men took a glass-bottomed boat to go up a river to see some greenery and alligators.

"We had a good time, he was so happy and always so brilliant," she said, "we thought he was doing so well, we just kept hoping and hoping."

O'Tierney's Instagram account shows his talent for landscape photography, a passion he embraces after leaving Square to travel the world.

The spelling of the surname is different because her parents, who are now separated, wanted O'Tierney to have more of a mark of their Irish heritage.

A memorial service will be held in San Francisco in the next two to three weeks, the family said.

Shwanika Narayan is a writer at the San Francisco Chronicle. Email: Twitter: @shwanika