The System Design Handbook
A structured journey from a single binary to a global, highly available architecture. Designed for engineers who want to build, not just memorize.
Choose Your Track
System design is a spectrum. Select the track that matches your current engineering focus.
Track 1: Foundations
0–2 YoEMaster the single binary, basic network routing, and standard database interactions.
Track 2: Distributed Shift
3–5 YoEBreak the monolith. Build decoupled, horizontally scalable backend services.
Track 3: Global Scale
6+ YoEDesign for failure, global consistency, and orchestration. Build systems that heal.
| Experience Level | Focus Area | Architectural Goal | Key Technologies |
|---|---|---|---|
| Beginner (0-2 YoE) | Client-to-Server | Making it work in production | HTTP, DNS, SQL, Load Balancing |
| Intermediate (3-5 YoE) | Server-to-Server | Decoupling & Speed | Caching, Queues, Data Replication |
| Advanced (6+ YoE) | Cluster-to-Cluster | Surviving catastrophic failure | Orchestration, Sharding, Consensus |
Engineering Modules
The Monolith & Its Limits
Where every system starts. Understanding vertical ceilings, OS constraints, and why a single server can only take you so far.
Network Protocols & DNS
DNS resolution, TCP/UDP transport, TLS encryption, and HTTP semantics — the full lifecycle of a request from URL bar to response.
Caching Strategies
Cache-aside, write-through, write-back, and eviction policies (LRU, LFU, FIFO). Master the art of saving results to avoid redundant work.
Scaling Out
Breaking the vertical ceiling. Stateless mandates, horizontal scaling, and the tradeoffs of distributing your application layer.
Load Balancing
L4 vs L7 distribution, health checks, sticky sessions, and algorithms like Round Robin, Weighted, and Least Connections.
Asynchronous Architecture
Decoupling with message queues vs event streams. Handling dead-letter queues, idempotency, and back-pressure.
Database Scaling & Distributed Data
Replication strategies, sharding (hash, range, directory), CAP/PACELC theorems, and consistency tradeoffs across nodes.
Database Indexing
B-Tree and Hash indexes, composite keys, covering indexes, and eliminating full table scans for O(log n) lookups.
Orchestration & Resiliency
Containers, Kubernetes, circuit breakers, retries with backoff, and securing the perimeter. Design systems that heal themselves.
Advanced Caching & Invalidation
Cache invalidation at scale: race conditions, stale sets, lease-based caching, CDC pipelines, Redis Cluster, CDN purge strategies, and multi-layer cache coherence.
NoSQL & Purpose-Built Databases
Document stores (MongoDB), key-value (Redis, DynamoDB), wide-column (Cassandra), graph (Neo4j), vector databases, and polyglot persistence patterns.
The 4-Step Design Framework
Requirements, estimation, high-level design, deep dive. A repeatable mental model for system design interviews and greenfield architectures.
Applied Design: File Storage
Build S3 from scratch: blob storage, metadata service, erasure coding, multipart upload, pre-signed URLs, and 11-nines durability.
Applied Design: Social Feed
Fan-out on write vs read, hybrid model for celebrities, ML-based ranking pipeline, and timeline assembly at 500M DAU.
Applied Design: Real-time Chat
WebSocket connections, message ordering, presence optimization, offline sync, group chat scaling, and end-to-end encryption.
"The best way to learn
is by doing."
Every module includes Toolkit Side-Quests—interactive simulators where you can break, scale, and visualize the concepts you just learned.