CHICAGO — Upwork, a global freelancing website, has signed a 67,730-square-foot office lease at 525 W. Van Buren St. in Chicago. The Silicon Valley-based start-up launched its Chicago presence in 2017. Melissa Rubenstein and Gary Kostecki of JLL represented the owner, AEW Capital Management LP. Allen Rogoway, Janna Luce and Eric Nolin of Cresa represented Upwork. Completed in 2002, the 16-story office tower consists of 519,668 square feet. This year, AEW plans to renovate the lobby.