Amazon Software Development Engineer interview questions

I was contacted by recruiter on LinkedIn, scheduled for OA test. I cleared the Online Assessment test within 90 minutes plus some behavior questions and go on the phone screen with recruiter

Initial Screening: Call with the SDE engineer from the team that I was interviewing for. Behavioral question (15-20 mins) + Algorithmic question based on Binary trees. (Path between two nodes) Virtual On-screen Interview: Round 1(Bar Raiser): In-depth behavioral questions (25-30 mins). String manipulation question to incorporate discount calculations. Round 2: 50 mins coding question (To create a library/ package to implement functionality similar to couple of Linux commands ) + 10mins behavioral questions Round 3: 20mins behavioral + 40 mins Singly Linked List manipulation based on their positions. Round 4: 15mins Behavioral + 45 mins object-oriented design based question for a library system