MERN stack role Round 1 - paper coding round leetcode easy -2 , medium - 1 , dp , recurtion and prefix sum Round 2 - F2F technical round , javascript basics like Clojure , Call stack , promises Round 3 - F2F technical round , React basics , virutuval dom , performance factors , temporal dead zone , DB indexing , LRU cache Round 4 - CTO round F2F Technical leetcode hard