These interview are notoriously hard to pass. Less than 5% gets in. You should not feel bad about it. Being an SRE at Amazon or Google scale require that you know what is going on in every layer of the infrastructure, including data structures in code, so that you can pinpoint the exact problem in the stack. I think some of these question are overkill and have nothing to do with how good you are going to be at the job though. Writing a binary tree certainly one of those. You are not going to write one because there are tons of libraries in every language that is in production. Knowing that DNS can use TCP is much more valuable. This falls into the category of questions that you are likely to run into when debugging an issue.
If you want to get a job at Google you have be willing to be put up with these questions (both the ones make sense and the ones do not) just to show your dedication. I usually prep for such interviews roughly 3 months and I have worked as an SRE for a long time. Do not assume that we know all of these things on the top of our heads and do not feel stupid.
If you want to get a job at Google you have be willing to be put up with these questions (both the ones make sense and the ones do not) just to show your dedication. I usually prep for such interviews roughly 3 months and I have worked as an SRE for a long time. Do not assume that we know all of these things on the top of our heads and do not feel stupid.