I will be starting out as an SDE 1 at Amazon next week and this is my first major job out of college. I have been working mostly on startups and I feel like expectations are high at a big tech company like Amazon. From what I know and from discussions with my HM prior to joining, I will be working with an unfamiliar stack and a lot of internal tools. How do I make the most out of my first week of onboarding, how do I learn the codebase that uses an unfamiliar stack so that I understand it very well and quickly become a valuable contributor to the team? Right now, I'm suffering from imposter syndrome and feel like I might not be good for the job.