Architecture 101: Building Up Complexity One Decision at a Time
The core idea
An architect's job isn't to draw every box on day one. It's to decide what to leave out, and to say "no — not yet" more often than "yes." Every box in the diagram below was added on purpose, to solve a specific, named problem. If you can't name the problem a box solves, you probably don't need the box.
There is no such thing as a universal "best practice." Companies like Netflix can afford mistakes you can't. What follows is a set of components explained in the order you'd actually reach for them, each one paired with the pain it removes and the pain it introduces.
The end state of this guide matches the full reference architecture below and by the end, every box in it should be justifiable, even if you choose not to use all of them.