Facebook said it has shaken up its engineering teams to make targeting smartphones a top priority at the world's leading social network.

"We have really just re-organized the company to build faster on mobile," Facebook director of product management Peter Deng said during a briefing with reporters at the company's campus in Menlo Park, California.

"In the past six months we transplanted mobile engineers to the other teams," he continued. "Slowly, over time we are making everyone a mobile engineer."

Facebook users have been shifting from accessing the social network on desktop computers or laptops to smartphones and tablet computers, where the company doesn't serve-up money-making ads.

About 7,000 different models of mobile devices are used daily to connect with Facebook and the challenge is to tailor experiences for each gadget, according to Facebook product manager Mick Johnson.

A focus on HTML 5 technology to connect across the spectrum of smartphones using mobile Web browsers resulted in lackluster results, according to Facebook.

"The performance wasn't what our users expected and we weren't happy with it either," Johnson said.

Facebook released a rebuilt application for iPhones a few weeks ago and saw its rating in Apple's online App Store go from two to four stars.

"Internally, we are psyched," Johnson said. "This is really just the start of the road for us; there are many things we want to do."

Facebook director of developer products Dough Purdy pulled an iPhone from one pocket of his jeans and an Android-powered smartphone from another, referring to them as the most social devices people have ever had.

Giving outside developers tools to optimize Facebook-synched applications for users of Apple or Android gadgets is part of the company's intensified focus on mobile, according to Purdy.

"Facebook has become a powerful engine for third-party developers to acquire new users," Purdy said. "And gaining new users is the name of the game; it is how you make money in this new world."

About 225 million people each month go to the Facebook App Center, which helps people find "social" applications based on factors such as what friends at the social network like.

"We are trying to deliver the best user experience whatever platform is available," Purdy said, noting that Facebook engineers remain bullish on HTML 5 technology for connecting with people through Web browsing software.

"HTML 5 is great to give us reach because most devices have some kind of Web browser," he explained. "We are building native applications for Android and iOS, but we can't build for all the devices that exist."

Android and Apple devices dominate the smartphone market. Facebook has started Android and iOS training sessions and expected to have 200 to 300 engineers trained by year's end.

Purdy saw "huge" potential for Facebook to make money from the shift to mobile devices, including getting revenue from helping people find things from shops or restaurants to "apps."

"What is Facebook really?" he asked rhetorically. "Word of mouth at scale."

Facebook founder Mark Zuckerberg said Tuesday the social network giant is focused on mobile devices and should be seen as a smart bet despite a "disappointing" stock market debut.

"It is really clear from the stats and my own personal intuition that a lot of energy in the ecosystem is going to mobile, not desktop (computers)," Zuckerberg said during an on-stage interview at a TechCrunch Disrupt conference in San Francisco.

"That is the future," he continued. "We are going to be doing killer stuff there."

Zuckerberg was adamant that the company was being underestimated and was on track to make "more money on mobile than we make on desktop."

His appearance at the conference marked his first public interview since the massive public offering on May 18 that was hotly anticipated – but ended up being a flop.

Facebook shares debuted at US$38 a share but were $20.71 at the close of trading Thursday on the Nasdaq.