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When Jeff Bezos revealed in May that Amazon employed more than 1,000 people working on Echo and Alexa products, he warned: “It’s just the tip of the iceberg.”

Here’s some proof. The Echo and Alexa groups are currently looking to fill 400 positions, according to Amazon’s Alexa job page.

The open positions run the gamut from data engineers to product managers to machine learning scientists. And the job locations are as varied: From Amazon’s headquarters in Seattle to other U.S. cities like Tempe, Ariz.; Cambridge, Mass.; and Sunnyvale, Calif. Overseas, Amazon’s voice technology groups are also hiring in places like Gdansk, Poland.

The hiring push comes as Amazon has recently added new devices to its line of Echo voice-controlled speakers, the success of which has been a surprise to even the most optimistic Amazon insiders. In September, Amazon introduced a cheaper $49 Amazon Echo Dot, which syncs up with traditional speakers to allow them to respond to voice commands.

Amazon has also been pushing to get other companies to integrate the Alexa voice assistant technology into their own devices. Amazon isn’t charging for the service and believes it can come up with a business model once the technology becomes ubiquitous. Obviously, shopping by voice commands will be one component.

The future of internet search is up for grabs, and Amazon wants Alexa to be the new front door.