Less than three years ago, GeekWire started a database to track the staggering number of out-of-town tech companies setting up engineering centers in Seattle, and since that time, the list has doubled in size.

RELATED CONTENT Check out GeekWire's list of Seattle-Area Engineering Centers established by out-of-town companies. The announcement of Chinese search giant Baidu’s new office in Bellevue, Wash., this morning brings the number to more than 100, and despite our diligence in documenting this trend, we’ve probably missed one or two along the way. So what’s behind Baidu’s decision to open an engineering center in the Seattle area, and the trend of these outposts in general?

“Talent, talent, talent,” said Baidu president Ya-Qin Zhang, who established and led Microsoft’s China R&D initiatives before joining Baidu. He cited the region’s growing status as a magnet and home for leading computer scientists and engineers, particularly in cloud technologies.

All that talent has helped propel Seattle to become the second best tech market in the nation, behind only San Francisco, according to a July report from real estate company CBRE. The report shows there are 136,910 tech jobs in Seattle, a 33 percent increase since 2011, and these workers are well-paid, with an average wage of $113,906.

The list of engineering outposts today includes a who’s who of the world’s top technology companies: from giants like Apple, Google and Facebook to global powers like Alibaba and Tencent to some of the world’s most valuable startups like Uber and Airbnb.

The engineering outpost trend really got rolling more than a dozen years ago when Google identified the region as a hotbed of talent, primarily pulling engineers out of Microsoft. Since then, Google has established big offices in Kirkland and Seattle’s Fremont neighborhood and is building a new campus in Amazon’s backyard of South Lake Union.

Several other big tech companies have followed Google’s lead in establishing outposts and growing to become major players in the local ecosystem. Facebook is another example. It first came to Seattle in 2010 with a small office near Pike Place Market for just a couple of people.

The social giant last year opened a huge new office with room for 2,000 people, and then just a few months later turned around leased two other office projects.

The new engineering centers are very much transforming the Seattle tech community as we know it, adding more competition for Seattle’s tech talent all the time. But the continued influx of these companies also is diversifying the tech landscape of Seattle, creating a more vibrant tech ecosystem that goes beyond the historical roots of Amazon and Microsoft.