Started with a phone screen, just asking questions relating to my experience and how they aligned with the job description. After that, had a 1 hour teams meeting with the hiring manager, who asked questions about my resume, and then some technical questions related to challenges they face at WHOOP. The third (and final) round was onsite, 3 hours long. You meet with industrial design, marketing, project management, other mechanical engineers, and the hiring manager again to talk experience. There is also a technical challenge with the MechEs, simulating how you would develop a new product. The process was generally good, but after I got rejected I asked for feedback and they didn't really give me anything tangible.