first we have a phone interview about coding problem, and then need to join 4 rounds onsite virtual interview about coding and system design questions, from medium to hard difficulty.

Standard phone interview/screening; hour-long technical interview with Leetcode-style question, followed by a 4-hour long onsite with behavior/cultural fit and a systems architecture question. They were very interested in knowing how you would think about designing a system from the ground up and how you would solve problems