System Design coming from a purely Systems / Cloud Infra background

I've been preparing for what I think is my 3rd interview for an infrastructure role that includes a system design component. And I have to say, as someone who had heard of leetcode and system design but never actually sat down and practiced it before this, my imposter syndrome has somehow... grown. Never in my career have I felt the absence of a CS degree more than when I'm being asked to articulate APIs and data models for things like a Dropbox clone, a