Facebook has hired the team behind the San Francisco-based user experience research and design firm, Bolt Peters.

Bolt Peters will end operations on June 22 to join Facebook’s design team. The firm has fewer than 10 people, but it is unclear how many of them will become employees of the social network. The company, co-founded by CEO Nate Bolt in 2002, has done work for Twitter, Zynga, Pandora and dozens of other well known clients. It also spawned a standalone company, Ethnio, which provides a way for websites to recruit visitors for real-time research. That company will continue to run independently.

As Facebook expands its reach throughout the world and designs experiences for multiple devices, the social network needs a strong grasp of how users interact with the platform. It is constantly testing variations in design and functionality, and the Bolt Peters team could provide a lot of value in pushing usability forward.

In a blog post announcing the move, Bolt says, “We’re stoked about Facebook’s commitment to user experience, and the design team is a critical part of this.”

Facebook did not provide comment or details beyond what Bolt included in his post.