How software really works, drawn by hand.
A notebook of plain-English explanations and scribbled diagrams on system architecture, databases, and the courses worth taking. Pick a page and start reading.
A tiny system
1/5 You click a link, and your request sets off.
System Architecture
Architecture styles, trade-offs, how to design a system, and C4 diagrams at every level.
26 topics
Database Concepts
Keys, normalization, ACID, indexes, replication, sharding, CAP and NoSQL.
9 topics
AWS Scaling
Load balancing, Auto Scaling, Lambda, queues and databases that grow with you.
13 topics
DevOps
CI/CD, Docker, Kubernetes, safe releases, observability and incident response.
19 topics
VPS Deploy
What to do after buying a VPS, and what goes wrong at each step if you skip it.
15 steps
Subjects
From engineering maths and C to Arduino, Nuvoton and real-time Raspberry Pi.
16 subjects
Courses
A hand-picked path from your first program to distributed systems.
7 steps