Learn
Pick a track to see its chapters in reading order. No background is needed. If a chapter lists an "after", finish that chapter first.
- Pass a system design interview→ System Design, chapter 1
- Understand how an LLM works→ AI, chapter 1
- Get good at coding problems→ DSA, chapter 1
- Ship and run things in production→ DevOps, chapter 1
18 tracks · 100 chapters · 583 lessons
Part one · Start anywhere
System Design24 chaptersWhat breaks as one service gets popular - caches, queues, replicas, shards - then the interview, then real companies read through it.
- The stall gets famous5
- When the stalls must agree5
after The stall gets famous
- Holding up under load1
after The stall gets famous
- The parts, properly4
after The stall gets famous
- The interview, assembled2
after Holding up under load, The parts, properly
- The stall, built0
after The interview, assembled
18 case studies, one system each, in any order162
after The stall gets famous
How Computers Work5 chaptersOne trick - a switch that is on or off - made into numbers, real numbers, and the gates that add them, each with its byte-level close-up.
- Bits and switches5
- The machine runs a program6
after Bits and switches
- Many programs, one machine4
after The machine runs a program
- Inside the operating system0
after Many programs, one machine
- Build the machine's software0
after Inside the operating system
Networking5 chaptersDNS resolution told as a concierge story, the same question as bytes on the wire, and the telegram written by hand.
- Names into addresses4
- How a packet finds a house4
after Names into addresses
- Faster, private, everywhere4
after How a packet finds a house
- The whole trip0
after Faster, private, everywhere
- Build it yourself0
after The whole trip
DSA10 chaptersThe judge for speed and the core structures, then how to pick an attack, then clinics that drill it on real problems.
- The toolbox7
- Choosing the attack4
after The toolbox
- Worked, and deeper6
after Choosing the attack
- DSA, in Hinglish10
- Clinic: arrays, hashing and stacks7
after The toolbox
- Clinic: search, trees, graphs and heaps9
after The toolbox
- Clinic: recursion, backtracking and DP6
after The toolbox
- Worked problems, in English0
after The toolbox
- Built from the toolbox0
after Choosing the attack
- Git Diff9
after The toolbox
Data Systems3 chaptersWhat a data system promises; the shapes data can take; how a database lays bytes on disk; how those bytes survive a change of format; and transactions that keep them straight.
- Data on one machine6
- Data on many machines4
after Data on one machine
- Data in motion3
after Data on one machine
AI8 chaptersFrom one neuron's weighted sum to a working LLM, then the apps built on one and the fleet that serves it.
- Neurons to a language model5
- From a model to an app5
after Neurons to a language model
- Past the basics7
after From a model to an app
- The string and the contract4
after Neurons to a language model
- The loop and its harness7
after The string and the contract
- GPT, built from scratch0
after Neurons to a language model
- On a real model0
after The loop and its harness
- Serving LLMs6
after Past the basics
Mind Blown8 chaptersNumbers that run away, logic that bites back, waves, matter, space and time, your body and your mind.
- Numbers that run away9
- Where logic bites back9
- Waves: sound and light7
- What stuff does8
- Space, time and the very small6
- Your body6
- Your mind5
- Earth, sky and deep time0
How Things Work2 chaptersWhy time has a direction, why cold is a lie, why a fan cools you and not the room, why a lid cooks faster, how a screen fakes every colour, and why glass is clear.
Open the track page →Psychology2 chaptersHow the field checks a claim and the brain it studies, then memory as a desk between a firehose and an archive, spaced repetition, cognitive biases, decisions under uncertainty, attention, habit, and how expertise forms.
- How the Mind Works7
- The Whole Person0
after How the Mind Works
Game Theory2 chaptersStrategic interdependence, from the Nash equilibrium and the prisoner's dilemma through repeated games, Schelling points and mechanism design.
- The Math of Strategy7
- Moves in Time0
after The Math of Strategy
Finance3 chaptersYour own money first, then how markets price risk, then the pipes that move every payment.
- Your Money2
- Markets4
after Your Money
- The Plumbing That Moves Money3
after Markets
Short tracksPersonal DevelopmentPhilosophy
Part two · Build on it
From Scratch13 chaptersRebuild the tools you use - an HTTP server, Redis, Kafka, a database, a scheduler, a sharded key-value store, Kubernetes, Raft, an LSM tree, git, a DNS server - one layer at a time.
- Enough Go0
- Redis9
- HTTP Server9
- Kafka9
- Database9
after One Database, to the Bolt (Database Internals)
- LSM Tree0
after One Database, to the Bolt (Database Internals)
- Distributed Scheduler9
- Sharded KV store0
after The stall gets famous (System Design)
- Raft0
after Data on one machine (Data Systems)
- Kubernetes9
after Kubernetes (DevOps)
- Git0
- DNS Server0
- Container Runtime0
DevOps10 chaptersContainers, Kubernetes, cloud networks and identity, CI/CD, and the platform a company runs its teams on.
- Containers & Docker4
- Kubernetes10
after Containers & Docker
- Regions, networks and doors9
after Names into addresses (Networking)
- One machine, one proxy, one bucket4
after Regions, networks and doors
- Who may do what6
after Regions, networks and doors
- Rooms someone else runs0
after One machine, one proxy, one bucket, Who may do what
- CI/CD, IaC & Operations4
- Ship it0
after CI/CD, IaC & Operations, Kubernetes
- AI/ML Ops9
after Neurons to a language model (AI), Kubernetes
- The Paved Road9
One chapter eachPortfolio ProjectsDatabase Internals (needs The parts, properly (System Design))Security