LARSEN, Circuit Judge. Jason Schwebke sued his employer, United Wholesale Mortgage (UWM), alleging disability discrimination under state and federal law. For seven months, UWM participated in extensive discovery—producing tens of thousands of pages of documents, taking and defending depositions, and issuing third-party subpoenas—without ever mentioning arbitration. Then, with discovery nearly complete, UWM moved to compel arbitration. The district court denied that motion because UWM implicitly waived its arbitration right. We AFFIRM.