John handles a variety of patent-related matters, including litigation in federal district court and appeals before the U.S. Court of Appeals for the Federal Circuit, client counseling, license drafting and negotiations, patent post-grant proceedings and European opposition proceedings. His practice focuses on patent litigation on the trial and appellate level, and he has represented clients in diverse fields, such as consumer electronics, automotive components, medical devices, paper making processes and chemicals, inks, vaccines, pharmaceuticals, e-commerce, and toys and children's products.

Early in his career, John served as a law clerk to the Honorable Paul V. Gadola, U.S. District Judge for the Eastern District of Michigan. During this clerkship, John gained extensive familiarity with federal civil and criminal trial practice.