***This post was written by Peter Delevett and appeared at WireTap in the San Jose Mercury***
When word broke Monday morning that Facebook was buying a tiny San Francisco startup for $1 billion, many asked: "Who are these guys?"
Instagram, which makes a wildly popular app to turn mobile-phone photos into mini works of art, has a staff that barely tops a dozen. And at the top of the org chart are a pair of co-founders just a few years removed from their Stanford undergraduate days.
Kevin Systrom graduated from the Farm in 2006 and has worked at Google (GOOG) and the forerunner toTwitter. Co-founder Mike Krieger is even younger, a 2008 Stanford grad from Brazil who, before Instagram's launch, had only held one full-time job, and that for less than 18 months.
Both men, through a Facebook spokesman, declined an interview request. But people who have worked with them say they benefit from a winning combination of technology chops and people skills.
"You could see how passionate they were," said Rob Abbott, a former adviser at San Francisco startup accelerator Dogpatch Labs, where Systrom in early 2010 launched a location-sharing service called Burbn. Abbott remembers being struck by the hours the young Stanford alumnus put in long after his peers had gone home.
Burbn attracted a small but devoted following of techies, including Twitter co-founder Jack Dorsey, who later invested in Systrom's startup. Back them, subscribers to the service had to post photos via email, an unwieldy workaround but nevertheless one that occupied an increasing amount of Burbn's traffic.
"Kevin came to me one day and asked, 'Rob, if I just focused on photos, would that be a good idea?' " Abbott recalled. "I told him, 'I need a Twitter for photos, and if you don't build that product today, I'm going to start working on it tomorrow.' "
Abbott became the first public user of the Instagram service and helped write some of its initial HTML code. Systrom offered him a job, but Abbott, who was focused on building his own mobile-design agency, Egg Haus, declined -- a move that as of Monday had probably cost him tens of millions of dollars.
But rather than admitting regrets, Abbott said he's delighted for Systrom, who he called "the hardest-working person I've met." Systrom taught himself to develop apps for Apple's (AAPL) mobile operating system and focused constantly on tweaking the product. Abbott praised his intuition and decision-making, which he called key to Systrom's ability to land $500,000 in seed funding from Netscape co-founder Marc Andreessen and Steve Anderson, a Microsoft and eBay (EBAY) alumnus.
Yet as skilled an engineer as Systrom is, he brought in Krieger to be his "more technical" co-founder, Abbott said.
"Mike's fantastic with people, and he's fantastic with technology," said Elaine Wherry, co-founder of Mountain View startup Meebo, which lets users bookmark information from around the Web, find new items of interest and share them with friends.
Krieger was still an undergrad when Wherry visited Stanford to help judge a student technology competition. Krieger stood out in the crowd. "He really had insightful things to say about other people's projects," Wherry said. Over coffee, she invited the youngster to join her startup, which was then just a few years old.
Once he started, Wherry said, "It was quickly apparent that he was more talented than anybody, even with zero experience. He's the kind of person who thinks deeply, and he's always thinking about product." She wasn't the least surprised when Krieger eventually broke the news that he was leaving to co-found his own company.
Wherry and Abbott both said they expect Instagram's founders not to be content to rest on their laurels at Facebook but to found new startups down the road.
"Whatever Kevin does next," Abbott said with a laugh, "I'll say yes if he asks me to join him."
Contact Peter Delevett at 408-271-3638 or pdelevett@mercurynews.com. Follow him at Twitter.com/mercwiretap.
meet the valley's newest moguls
Kevin Systrom: Graduated from Stanford University in 2006 with a bachelor's degree in management science and engineering. Interned at Odeo, which morphed into Twitter. Spent two years at Google, working on Gmail and in corporate development. Co-founded Instagram in March 2010. Website: www.systrom.com.
Mike Krieger: Graduated from Stanford in 2008 with bachelor's and master's degrees in human-computer interaction. Interned at Microsoft. Worked at Mountain View startup Meebo for 17 months before co-founding Instagram. Blog: http://mikeyk.wordpress.com.
SNAPSHOT OF INSTAGRAM
Founded: 2010
Based: San Francisco
What it does: Lets users snap photos with an iPhone or Android phone, add visual effects and share with friends on Instagram's network or through Facebook, Twitter or other social networks.
User growth: Instagram has more than 31 million members, up from about 1 million at the start of 2011 and more than double the number at the start of this year. The service currently has about 7.3 million regular users who post photos at least once a month. It had more than 1 million downloads in the 12 hours after launching its Android app last week.
Employees: About a dozen.
Sources: Wedbush Securities Private Shares Group, AppData.com, Business Insider.