No problem! It’s a great place to start, because you will get exposure to every line of business / product and also learn how the money moves. It’s definitely old school Amazon, they have higher standards than most of the other teams.
I worked in a sister org and a lot of our work overlapped. Not sure on the WLB, it probably depends on the project. On call is probably pretty bad since it’s a tier 1 service. If you can’t calculate taxes, you can’t buy things.