Who's behind this

The person

I'm Felipe Rodrigues, a frontend developer in Florianópolis, Santa Catarina, Brazil. More than six years in React, TypeScript and Next.js. That is the interface layer, which is where you end up feeling every decision the backend already made for you.

I started writing this because I wanted to understand how the systems underneath my components actually work. Not the vocabulary, the reasoning: how the people making those calls decide to scale an app, connect its pieces, and serve a few million users without the whole thing drifting out of consistency.

Those answers are already out there, and they are well organised. ByteByteGo, DesignGurus.io, roadmap.sh and index 0 all cover this ground, and index 0 is where much of the source material for these pages comes from. This is not an attempt to replace any of them. I needed my own way of working through the material and tracking what I had actually covered, so I documented each concept here in the order that made sense to me.

It is built for me first, and for anyone else who feels like learning something new.

The project

A free, self-study roadmap through system design fundamentals: scaling, databases, caching, APIs, and the trade-offs underneath every distributed system. No signup, no paywall, no email capture. That is not a launch promise, it is the whole design.

Every concept is one self-contained page: the big idea, why the problem exists, an analogy, the mechanism, worked examples and diagrams, what real systems do, the common mistakes, and a quiz to check what actually stuck. No prior background assumed, and you can read them in any order.

I am not writing these from expertise. I read, and then I document what I read, because writing it out is what makes it stick and what stops me fooling myself about how much I have actually taken in. The roadmap doubles as a record of my own progress, and putting it somewhere public is the part that keeps me committed to finishing it.