41
Interactive drills
What you get
Two of these are free forever. The other five are Pro, and none of them has shipped yet — every card says which.
8 tracks · 41 modules · 204 lessons · free
Design the system.
Then defend it.
A complete system design curriculum, from what a TCP handshake costs to a payment ledger that balances — and the drills that make you choose a trade-off and pay for it. Free, all of it.
6
Systems, end to end
159 hours
of curriculum, free
of curriculum, free
8 tracks
network to negotiation
network to negotiation
Everything free
Pro, at $5,900, is only for getting hired
8 tracks, 41 modules, none of it behind a paywall
01 · Foundations
02 · Data Storage & Retrieval
03 · Caching & Delivery
04 · Messaging & Event Streams
05 · Scaling & Traffic
06 · Reliability & Operations
07 · Design Case Studies
08 · The Interview Loop
01 · Foundations
02 · Data Storage & Retrieval
03 · Caching & Delivery
04 · Messaging & Event Streams
05 · Scaling & Traffic
06 · Reliability & Operations
07 · Design Case Studies
08 · The Interview Loop
01 · Foundations
02 · Data Storage & Retrieval
03 · Caching & Delivery
04 · Messaging & Event Streams
05 · Scaling & Traffic
06 · Reliability & Operations
07 · Design Case Studies
08 · The Interview Loop
Where to start
Why this one
Built around the thing the interview actually scores: a decision you can defend.
The curriculum is free, permanently
Every track, every module, every drill. There is no paywall partway down a page and no chapter that stops mid-sentence. The paid product is the interview machinery, and it is a different thing.
Trade-offs, not vocabulary
Naming a pattern is not designing a system. Every module ends in a drill that makes you choose, then shows you what the choice cost — which is the thing an interviewer is actually scoring.
Built for the round you will sit
Forty-five minutes, one whiteboard, one interviewer who will push back. The last track is about running that specific performance, because knowing the material and passing the round are two skills.
Nothing here is invented
No testimonials, no placement statistics, no graduate count. Nobody has taken this course yet, so there is nothing to report — and we would rather say that than fill the slot.
Explore the curriculum
How this works
01. Start where you actually are
The first track assumes you can write code and nothing else. If you already know what a quorum read costs, skip to track four — every module lists what it expects you to know.
02. Read a little, then argue
Concepts are introduced briefly, because reading about consistency is not what makes it stick. The drill at the end of the module is where the learning is.
03. Work the case studies out loud
Six systems, worked end to end. Do them narrating, at a whiteboard, against a clock. That is the format you will be tested in, so it is the format to practise.
04. Run the loop
Question bank, mock rounds with the community, and a tracker that remembers what each company asked. The last track is about the forty-five minutes themselves.
Frequently asked questions
Is the curriculum really free?
Who is this for?
Is any of it available yet?
Why are there no testimonials or success stories?
Does the application assistant apply to jobs for me?
What does Pro cost?
