Having once worked on a 200-person oil tanker while serving in the French navy, Dufétel moved on to the U.S. for grad school. Then it was on to finance, where she was most recently the CFO and COO at T. Rowe Price, the global investment manager with $1.6 trillion in assets under management. Now, after nearly four years at the financial services giant, Dufétel tells Fortune that she will soon be joining Checkout.com, a London-domiciled cloud-based payments company that is one of the highest-valued startups in Europe—worth a hefty $15 billion. She will take on the role of CFO at Checkout.com in early September.

“I think that I’ll bring a lot to Checkout, and I think Checkout will bring a lot to me in terms of new experiences,” Dufétel tells Fortune. “It’s a new space for me, first and foremost, and then it’s a different stage in the company’s life than I’ve been part of before, so I’m super excited about it.”

Dufétel’s move comes at a time when the U.K. unicorn (or, rather, decacorn) is growing rapidly—both in terms of its business and valuation.

Checkout.com provides payments services, data insights, and fraud protection for its customers, which include crypto exchange Coinbase, fintech Klarna, fast-fashion retailer H&M, Singapore-based ride-hailing firm Grab, and e-commerce platform Farfetch.

The fintech counts big firms including Tiger Global Management, DST Global, and Insight Partners as its backers, having raised $830 million in funding to date—including, most recently, a $450 million Series C round in January. (Dufétel and Checkout.com founder and CEO Guillaume Pousaz were introduced through Insight Partners managing director Deven Parekh.) Checkout.com has also seen a surge in transaction volumes, which tripled last year, fueled by the acceleration of contactless payments as shoppers and merchants continue shifting online.

“I think it’s a really exciting time to be joining the firm because of where it is in its growth trajectory, but also because of the leadership changes that are happening,” Dufétel says.

Indeed, she isn’t the only new hire. So far this year, Checkout.com has nabbed Ott Kaukver (formerly of Twilio and Skype) and Nick Worswick (formerly of WeWork and Grubhub) as chief technology officer and chief revenue officer, respectively, to bolster its executive ranks.

Courtesy of Céline Dufétel

But the choice of Dufétel as CFO is particularly eyebrow-raising, given her C-suite role at a large public company—fueling speculation over an upcoming IPO (CEO Pousaz has called it a “natural step” for Checkout). “Hiring Céline, with her public market experience from such an established organisation, is really about learning how to be best in class and ensuring we’re building strong foundations so we’re ready for an IPO when we decide it’s the right time,” Pousaz told Fortune via email.

However, it seems that “right time” isn’t right now: Pousaz says that while an IPO is the “likely path” for the fintech, “we still have a lot to do before we go public,” adding that “as a profitable company growing at triple digits we aren’t in a rush.”

Scaling up

Certainly competition in the payments space is fierce, and Checkout.com is facing some formidable rivals, including U.S.-based Stripe (valued at a whopping $95 billion) and Netherlands-based Adyen (which is publicly traded). While Stripe is expanding further into Europe, Checkout.com is growing its footprint in the U.S. It also recently launched a “payouts” capability that enables its merchants to send funds around the world.

Dufétel, a Fortune 40 Under 40 honoree (as is Checkout’s Pousaz), says that it’s “early days in terms of setting priorities” for her first few months on the job. With “a company of this pace of growth,” she notes, there’s plenty to dig into—including “scaling the team, scaling processes, making sure that the controls, the governance, the operations, everything that we do is extremely robust and supports the kind of growth that Checkout is going through.”

As for what Dufétel hopes to bring from her former position at T. Rowe to her new gig? She cites her experience operating at that company’s scale, and “what that means from driving risk management, driving operational excellence, driving strategy at scale, and hopefully helping bring that to Checkout as it continues its trajectory and becomes a larger…and more mature firm.”