Boston has landed another high-profile, e-commerce office expansion, but this time it is homegrown, not from Seattle.

Online home goods retailer Wayfair has inked a deal for a 395K SF office in Back Bay, taking the Boston-based company to over 1M SF of office in the neighborhood. The new office, spread across 500 Boylston and 222 Clarendon streets, could eventually handle as many as 4,000 employees, the Boston Globe reports. Wayfair has just over 655K SF at its existing Copley Place headquarters.

Wayfair expects to expand into the new offices in early 2019. The company currently employs 3,500. The Back Bay deal is the latest in a string of office activity for the neighborhood that had notably taken a back seat to the Seaport and East Cambridge for much of Boston’s recent development boom.

DraftKings is doubling the size of its Boston headquarters when it moves from downtown to a 105K SF office at 500 Boylston. John Hancock Financial Services announced in March it will leave its 465K SF Seaport headquarters at 601 Congress St. by the end of 2018 and transfer all 1,100 employees to its 1.2M SF Back Bay campus.

Wayfair announced in November it was in the market for as much as 1M SF of office in Boston on top of its Copley Place footprint, and it is believed the company is still looking for an additional 250K SF of office after the latest expansion.

Wayfair’s 500 Boylston/222 Clarendon deal is Boston’s second-largest office deal of 2018, after its Seattle-based competitor Amazon’s 430K SF lease at the L4 block of Seaport Square.