This post has some good concepts, but I do not feel it helps you design good systems. It iterates options and primitives, but good design is when and how you apply them, which the post does not provide.

But isn't that type of advice the best we can have? Having read Designing Data Intensive Applications (DDIA) and some system design interview-focused books (like those from Alex Xu), I have noticed two types of resources:

* Fundamental books/courses on distributed systems that will help you understand the internals of most distributed systems and algorithms (DDIA is here, even though it's not even the most theoretical treatment)

* Hand-wavy cookbooks that tend to oversimplify things, and (I am intentionally exaggerating here) teach to reason like "I have assumed a billion users, let's use Cassandra"

I liked the article for its focus on real systems and the sensible rules of thumb instead of another reformulation of the gossip protocol that very few engineers will ever need to apply in practice themselves.