The short-supply of available engineers specialising in mobile apps is becoming a key bottleneck for companies looking to exploit the fast growth in smartphones and apps, reports the Wall Street Journal (WSJ). The newspaper lists several examples of US firms struggling to recruit app developers, which has forced them to increase wages, retrain software engineers, outsource work to third-party developers and set up offshore development labs to meet demand.

In the last year, the number of online job listings with the keyword “iPhone” in the text has nearly tripled, while the number with “Android” has more than quadrupled, according to listings search engine Indeed Inc. (see graphic). Meanwhile, the number of mobile development jobs offered on Elance.com, a freelancer website, doubled between the first quarters of last year and this year, twice as fast as growth on the site as a whole. “Almost all of our companies are looking for Android and iPhone developers,” said Bijan Sabet, a general partner at Spark Capital, a Boston venture capital firm, whose portfolio includes Twitter, Tumblr and OnSwipe.

This shortfall between supply and demand has put upward pressure on wages, says the newspaper. According to an October survey by technology jobs website Dice.com, about 31 percent of companies reported that average pay among mobile software designers and engineers increased at a higher rate than normal, mostly because of heightening competition for talent. The survey said the average mobile salary last October was about US$76,000, but that several companies had been forced to pay anywhere from US$90,000 to US$150,000 a year.

Some start-ups are investing heavily in offshore development as an alternative to paying high domestic wages. The WSJ cites the example of Boston-based Where, which runs a mobile ad network and location-based recommendation service, which last year opened a development centre in Croatia to supplement its 18-person US mobile engineering staff. The centre now employs seven mobile engineers.

Outsourcing development work has emerged as another strategy for addressing the shortage. This has reportedly been a boon for software development agencies such as 360mind and Pivotal Labs, which have done work for the likes of Twitter and Groupon Inc. The staff at 360mind, a 20-person mobile development shop, doubled last year, and is likely to double again this year, CEO Nick Dalton told the WSJ.