How Tinder Scaled Up So You Can Swipe Right

Tinder held a networking event at its West Hollywood headquarters recently, where CTO Maria Zhang and her team tackled the complexities of running a popular dating app, from stripping out legacy code and scaling up efficiently to introducing new languages and premium features.

China-born Zhang studied computer science at Tsinghua University in Beijing before completing her education in the US. She joined Tinder in April 2016, after stints at Microsoft and Yahoo; the latter bought her start-up, Alike, a dynamic behavioral data recommendations engine.

"When I introduce myself as the CTO of Tinder, I tend to get this silent, surprised reaction," Zhang told the crowd with a smile.

But Zhang has moved fast; within six months of joining Tinder, she tripled her engineering team and opened a satellite tech office in Silicon Valley.

At the Tinder event, co-hosted with Tech Ladies, Zhang introduced key members of her team: Jessica Hickey, Backend Platform Engineer; Alex Salvatore, iOS Engineer; Kate Yortsos, Lead Data Engineer; and Samantha Stevens, Director of Growth Products. It turns out 40 percent of Zhang's engineering and tech team are women.

"Having an innate understanding of female users is tremendously valuable for any product development team," Zhang told PCMag. "At Tinder, prioritizing having women on the development team and in leadership roles has allowed us to create an app that provides meaningful experiences for our userbase."

If you hadn't given much thought to what goes into running the dating app that may (or may not) be on your phone, Tinder currently handles 1.6 billion swipes and makes 26 million matches per day and has delivered 20 billion total matches to date. It has more than 200 employees, registered users in more than 190 countries, and recently topped the App Store's top grossing category thanks to its tiered pricing model.

Tinder's corporate parent, Match Group, which owns a whopping 45 dating product brands (including OKCupid and BlackPeopleMeet), reported revenues of $310 million in Q2 2017, a 12 percent improvement year-on-year. It also has a new CEO, Mandy Ginsberg, who got promoted from her role as CEO of Match Group Americas, and will take over in early 2018.

But as with all matters of the heart, there's been drama at Tinder since its launch five years ago. Co-founder Whitney Wolfe filed a sexual harassment and discrimination suit in 2014; she later settled and went on to found rival, female-centric dating app Bumble, which has focused on non-hookup features of late, including a challenge to LinkedIn called Bumble Bizz.

Tinder, however, is also looking beyond the mindless swipe, and how the pursuit of new relationships translate across the world. Samantha Stevens, Director of Growth Products, took her team to Rio de Janeiro for an ethnographic research project.

"We saw, first-hand, how 18-year-old college girls in Brazil think about dating and Tinder in completely different ways than we do here in the US," she said. "For example, our concern over 'who texts first' just doesn't occur to them."

Many international users also download the app, but don't register or use the service, Stevens said.

"We identified that the problem was the Facebook registration," she said. Tinder sign-ups are linked to Facebook, but "in certain countries, [Facebook is] just not that popular.

"Plus many people don't want to link their Facebook account to their Tinder profile; perhaps they use Facebook more for business, or family," she said. "So we changed the path to allowing users to register with their phone number and that lead to a surge in growth."

"Data literally drives every decision we make," confirmed Kate Yorstos, Lead Data Engineer. "Our pipeline, if it goes down, everyone knows about it, so we built in all these additional systems to reach 99.99 percent availability. For example, if AWS Kinesis goes down, we utilize a dead letter queue [to retain data] and configured it to deploy a rescue app so you can push a time range to pull data off Kinesis, and replay it right back into the pipeline [later]."

As Zhang wrote in one of her regular Tindev (Tinder Engineering) blog posts: "Our 'matching' algorithm is real-time and location-based. You could think of Tinder as one large search engine—but there's a twist. Other large, global search engines are unilateral: their algorithms are one-sided; there's no need to worry if the blue links will like you back :) Tinder's algorithm is bilateral: it's only a match if I like you and you like me back. We optimize for rewarding everyone. We are solving serious engineering problems that go way beyond the swipe."

If you're looking to upgrade your own romantic search functionality, Tinder this summer launched a new members-only premium service called Tinder Gold. This has added features such as Passport, Rewind, Unlimited Likes, five Super Likes per day, one Boost per month and more profile controls. For maximum efficiency, the new "Likes You" feature means you can browse all pending matches at a glance before moving on.

Tinder Gold got rolled out globally in late August and, according to the engineering team, members reported 60 percent more matches.

This article originally appeared on PCMag.com.