Sarah Friar is the top Silicon Valley tech executive you've probably never heard of, but certainly should know about.
"That fabulous CFO" as CNBC host Jim Cramer recently called her, was entrusted by Jack Dorsey to take his payments startup public and now takes on more than the traditional role of a finance chief at Square.
Friar is happy to be on home turf during a whirlwind visit to the UK where she's about to open Ormeau Baths, a tech incubator space to foster startups in the heart of Belfast, along with entrepreneurs and investors such as FanDuel founder Nigel Eccles.
And she's likely to find these visits home more frequent. Square launched in the UK just over eight weeks ago and is already expanding. Its newest product, Virtual Terminal, launched this week and means business can take payments at desktop computers, not just with mobile.
It demonstrates Square's focus on the region which Friar describes as big, with a good economy and vibrant small businesses, reaching for the famous "nation of shopkeepers" quote. The UK also has high acceptance of cards and more generally, technology, but there are still more than 2m businesses that don't.
"We know that when small businesses accept cards they never miss a sale, their businesses typically grow faster, but it's also now that they are collecting data," she says, pointing out how they can identify busy times and find insights to improve their business so they don't get "Amazoned" - overtaken because they are not online.
There are no UK specific figures yet as it's still too early, but "so far so good" she says.
Friar made the now common jump from Wall Street to Silicon Valley in 2012, well before her peers made it a trend (Ruth Porat joined Google in 2015 while Anthony Noto landed at Twitter in 2014 along with Imran Khan at Snapchat and Laurence Tosi at Airbnb).
She was clearly on to something.
A brief stint at Salesforce before moving to Square was preceded by a decade on Wall Street working for Goldman Sachs which she joined at the height of the dotcom boom as a tech analyst and banker in 2000. Having seen the boom turn to bust and then the financial crisis of 2008 hit, moving to Square in 2012 when it was just 200 people (it's now more than 2,000) "came back to wanting to have a bigger impact".
"I went into finance because certainly how I felt back in the day is, I love numbers… I admit I’m a total geek... tech is now becoming the place where you can make that [impact] happen much more so," she says of the switch.
"Economic empowerment is what drives us [at Square]. It sounds like quite a highfalutin mission statement, and yet I think being part of a mission driven culture and company is such a relief in life. It’s fun and you're proud of what you do every single day and I think Wall Street lost that. Some of that sheen really came off in the crisis and that caused a lot of people to question why.”
Square's IPO in late 2015, a year "professionally, personally, emotionally and physically probably the most daunting I've ever lived through" came at a time when there was a drought of tech listings and much hand wringing about a bubble. But, Friar says there was no better time and would do it all again.
"Our lead here [in the UK, Sarah Harvey] used to be at Tough Mudder and from what I can tell the two are very analogous," Friar jokes.
"We did chose to go public at a particularly tough time from a macro standpoint. The market... if you looked at indices like the VIX it was off the charts, no one was going public, anyone in their right mind was not running that gauntlet.
"The best companies come public in the toughest of times because only the best can get through that gate at that point in time. In good times you get a lot of coming behind on the coat tails. And a year and a half later it's put us in a really good position with a balance sheet that's now getting close to a billion dollars."
It also did a convertible debt offering in January that raised more than its IPO giving it more capital to be more "opportunistic" with.
Some might say that "two jobs" Dorsey is only doing what millions of working women around the world do everyday: managing two jobs if they work and also have children.
Critics are dubious of the entrepreneur's ability to run both companies in the long term, leading some to speculate on his Square heir apparent. Friar's name appears highly on such a list.
"I don't' know that I totally buy that. I think it makes a good story, but if you look at our team, it's a really well balanced team," she says pointing to the impressive line up of leaders Dorsey has assembled at Square: former Visa marketing chief Kevin Burke leads marketing and sales; ex-Apple engineering director Jesse Dorogusker leads hardware; Alyssa Henry who helped build Amazon Web Services leads engineering; and the man who built AdSense, the foundation of Google's advertising juggernaut, and helped lead Facebook's ad efforts, Gokul Rajaram, leads product.
"Personally it [Dorsey becoming Twitter chief executive] has been a wonderful part of career growth, so I've gotten to run products, support organisation, I get to go far field from what is thought of as a traditional finance person and that makes my job way more interesting, it keeps me excited about what I do," she says.
But in addition to Square, getting involved in Ormeau Baths, and being a mother of two, Friar has just added another string to her already impressive bow having recently joined the board of Slack.
She's its first female director at the unicorn startup, quite a difference from Square where half of the leadership team reporting to Dorsey are women, 60 per cent of the business report up to a female leader and a quarter of its board are women.
She calls "the bit in the middle" the hard part of addressing what she dubs as systemic bias.
Getting girls into Stem (science, technology and engineering) from the bottom and having mentoring - "you can't be what you can't see" - from the top that sets an example are areas to work on across technology, but, the middle part of the career, when often women are having children is a greater conundrum.
"How do we give them the resilience? Because it's not even about confidence. It's just sheer resilience. To stay through those moments when you're really tired or frustrated. But I also think we need to make sure they're not frustrated because of some general systemic bias. I think there are massive systemic biases, and not just in tech, in every walk of life," she says.
"It's not just a random thing that women have babies and all decide not to come back to work... as a society, we either care about it and we're going change it, or we pay it lip service but don't actually care," she adds.
And this is one area where Silicon Valley and Wall Street are alike: "They're both just as bad," Friar says, perhaps a little exasperated. "There's a lot of work to do in both industries."
She may be flying somewhat under the radar, but she's one of the most influential people in tech. Friar and Square are setting an example.