Instagram chief executive Kevin Systrom had a key position to fill in early 2016. He needed someone to revamp the photo-sharing service he'd co-founded with Mike Krieger six years earlier. After keeping Instagram's executive ranks intentionally small, Systrom was putting together a team to help him overhaul the site, which Facebook had bought in 2012. The objective was to get users – especially younger ones – to post more content on Instagram. At the time, Snapchat was growing fast among youthful social media users, thanks to fun features like photo filters and disappearing videos. Systrom had already poached some big names from his Silicon Valley rivals. In early 2015, Ian Spalter left YouTube to become head of design at Instagram, while six months later Yahoo's James Everingham was hired as head of engineering. The smartphone is eventually going to die, and Apple, Google, Microsoft, and Facebook are racing to kill it But Systrom needed someone to design and build new features and tools for the site. As he searched for someone to help him implement his product ideas, Systrom asked a friend – venture capitalist Elizabeth Weil – to arrange a dinner. Weil is married to Kevin Weil, whom she'd met when they were both students at Stanford University. Kevin Weil had quit the university's doctoral degree programme in theoretical physics to start working at Twitter in 2009, when the social media service had just 40 employees. After seven years at Twitter, he had worked his way up to executive vice-president, overseeing all of the company's products, including its consumer-facing site, advertising products and the Vine and Periscope video tools. So Elizabeth Weil arranged the dinner – a meeting that would lead to the hiring of a man who would subsequently help Instagram (and Facebook) to trump rival Snapchat. During the dinner, Systrom offered Kevin Weil the head-of-product role at Instagram, according to an interview Weil gave at Stanford. During the interview, Weil said, he turned Systrom down. He'd already resigned from Twitter, where user growth had begun to wane, and planned to take six months off to train for an 80km foot race down the American River in California. What's more, he and his wife had started a family. He was a great hire … he’s been a critical part of their [Instagram’s]success. Krishna Subramanian Weil, who is 34, was enjoying time off - but then he reconsidered. “I said ‘no’, then said to myself: why should I turn this down?” Weil recalled during the Stanford interview. Weil, a whiz at maths and later at physics, grew up in Redmond, Washington, home of Microsoft, where his dad had worked for two decades. After his own long stint with one company, Weil said: “I wanted to see how other companies did things.” Weil took the job in March 2016 – and then finished the American River 50 in April, where he placed fifth. "I like running long races," Weil said, a comment that should put fear into the hearts of Snap investors. “There's not a lot of tricks to running a 50-mile [80km] race; you just start running and keep going. People underestimate the value of fighting through it.” Equally as impressive is what Weil and the rest of the new Instagram team have managed to pull off in the last year and a half. Facebook is testing Messenger ads around the world "He was a great hire … a key player," says Krishna Subramanian, chief executive of Captiv8, a start-up that provides analytics to social media sites. "He's been a critical part of their success,” he says. Within months of Weil's arrival, the site began to roll out a raft of new tools and features to match what Snapchat was doing. The key was Instagram Stories, a feature that let users share photos and videos for up to 24 hours before they disappeared, mimicking the similar Snapchat Stories feature. Snapchat was the first to create the format … more power to them, they did a fantastic job. Kevin Weil In November, it began letting users post images and videos that disappeared right away – the feature that originally made Snapchat famous – and in May 2017 it added face filters, one of Snapchat's most popular features. Soon Instagram's growth in both users and ads began to surge. It was aided not only by the tools Weil, and others, helped get out the door, but also by a savvy digital marketing plan: Facebook sent repeated notifications to its own users telling them which of their online friends were already on Instagram. The plan worked. In June 2016, Instagram had 500 million monthly users. By April 2017, it had grown 40 per cent to 700 million. More users brought more online marketers. In late March, Instagram hit 1 million advertisers, double the 500,000 it had last September. As its growth accelerated, Snapchat's began to flatten out. In the first quarter of 2017, Snapchat’s number of daily users grew only 36 per cent from the previous year, to 166 million. Instagram Stories, meanwhile, has grown to 250 million daily users in less than a year on the market. Hong Kong restaurants adapt to Instagram food porn craze "It’s the fastest-growing product I've ever seen,” said Weil. Instagram, which Zuckerberg bought for US$1 billion five years ago, is expected to post sales of US$3.6 billion in 2017, according to the market research firm eMarketer. “A year ago, Instagram was a product for your highlights,” rather than a place where users posted content about more routine events in their lives, Weil said. In other words, it had not changed much since Systrom had started it back in 2010. "If people are going to post multiple times throughout the day, the product needs to be more ‘person-oriented’ than ‘feed-oriented’,” Weil explained. That meant allowing users to post not only square photos but videos of varying shapes, sizes and lengths. Weil, whose 30-person team [as of May] work “all in the same room”, also credits Systrom and Zuckerberg for maintaining Instagram's independence. “I give a lot of credit to the two founders … We're a tiny company that gets to be a superpower because we're part of Facebook,” Weil said. As for Snapchat, Weil does give them credit – up to a point. "Snapchat was the first to create the format … more power to them, they did a fantastic job," he said.