I have a phone interview with a recruiter first, we just talk about my resume and some basic behavior question, like why do you like Pindrop. Then they send me a homework to complete, which is about machine learning and signal processing. I have 2 hours to do it.

Was very good and had good question too. I had a phone call then onsite interview than good questions with managers. Very smart people and recuirter was very helful during the whole process.