Several other alumni from Facebook, Twitter and Google also have joined in recent months. Snap, which recently began selling picture-taking sunglasses called Spectacles, is adding engineering staff in London, led by Ricky Leatham, a former Amazon.com development manager.
A spokeswoman for Snap confirmed the new hires.
The growing popularity of Snap's photo-sharing app makes it one of the most anticipated technology IPOs in years. The listing, which may come as early as March, could value the social-media platform at $20 billion to $25 billion, people familiar with the offering have said.
The company's 150 million daily active users are predominantly located in the US, but it's gaining popularity globally. A spokeswoman for Snap said it has 50 million daily active users in Europe, including more than 10 million in the UK and more than 8 million in France.
The expansions in London and Paris are part of a broader hiring binge. Snap has more than 150 job vacancies listed on its website, the majority at its Los Angeles headquarters.
London is a global hub for advertising, the main source of Snap's revenue.
The company initially attempted to maintain a small footprint outside the US, relying on partners to sell ads, according to Rob Norman, the chief digital officer of GroupM, which works with many California technology companies. Now the company is adding staff to take on more responsibilities internally, he said.
"They have made a decision to get more hands on in terms of controlling the sales of their product," Norman said. "They are hiring aggressively in London."
Snap's global advertising revenue will reach an estimated $366.7 million this year, and jump to $935.5 million in 2017, according to eMarketer Inc.
Snap has most of its non-US job listings in London, which is often the first port of call for American technology companies expanding in Europe. Snap is paying roughly 925,000 pounds ($1.2 million) per month for its office in London's Soho neighborhood, according to Edward Charles & Partners, the property agent. The lease includes the provision of a two-bedroom apartment.
Snap's growth plans are a vote of confidence for the London tech scene, where policy makers, venture capitalists and startup entrepreneurs have voiced concerns the city's standing would diminish after the UK's vote in June to leave the European Union. Google, Facebook and Apple Inc. also are expanding in the city.