System Design
Designing systems at the whiteboard, including the AI-shaped ones.
Design Fundamentals
How to run the round — scope it, size it, draw it, and defend the choices.
7 topics
Frontend System Design
The frontend design round — RADIO, the building blocks, and the prompts that keep coming up.
14 topics
Building Blocks
The components every design is assembled from, and what each one actually buys you.
11 topics
Scalability
What you do when one of everything stops being enough.
8 topics
Distributed Systems
The theory you actually get asked about — consistency, consensus, ordering, and partial failure.
9 topics
Reliability & Operations
Designing for the day it breaks — targets, containment, and what you can see from the outside.
10 topics
Classic Problems
The prompts that keep getting asked, each worked through to a defensible answer.
10 topics
AI System Design
Designing the systems these companies actually run — gateways, retrieval, agents, evals, and the bill.
11 topics
Low-Level Design
Design below the service line — the classes, interfaces and state machines behind one box.
5 topics
Architecture Decisions
The recurring arguments — split or don't, events or calls, build or buy — and how to write the decision down.
8 topics