Quick thoughts: - System design interview changes depending on the company. At Facebook the interviewer said one sentence in the whole interview to me, no fe

Quick thoughts: - System design interview changes depending on the company. At Facebook the interviewer said one sentence in the whole interview to me, no feedback or anything, so be prepared for nasty ones. At Google they hate if you use a particular product to solve your problem and everything needs to be backed up by numbers; they'll ask you how many servers you'd need for your solution ("bill of materials"). - Expanding on last comment, it's common to see in books and courses a basic math of number users -> estimate usage -> requests per second and storage needs but I've never seen anyone take one estimates about servers by computing processing (CPU/RAM) needed. - This guide, like almost all resources in particular takes on the most common case of web design: client-server request/response (plus queuing). There are other completely different paradigms that show up less frequently and are harder to have experience on, like streaming and batch processing. - As all guides given space/time limitations, some key concepts are hand-waved with a recipe-based approach.