Gainsight Senior Software Engineer interview questions

Got a call from naukri. Invited for the interview on Saturday. Had 3 rounds of discussion 1) Java , oops , multithreading, hashmap internal implementation, binary tree questions - height of tree, mirror image of tree , project discussion, 2) Design - Was given a choice to design either Uber / Amazon like service. Choose Amazon. Involved HLD and LLD for a use case of product listingg., SQL , reporting queries.. etc. 3) Managerial round - nothing tech. Just a formal one. 4) Skype call HR.