Learn how real systems are built, one lesson at a time.
Structured courses on system design, data structures & algorithms, AI engineering and machine learning, with diagrams, worked examples and trade-offs in every lesson.
- 4 courses
- 467 lessons
- 1193+ diagrams
- 104 hrs of reading
Pick a track
Each course is ordered into stages and parts, so you always know what to read next.
System Design
From one server to planet-scale systems.
A complete path through high-level design: the networking and database basics everything rests on, the building blocks you combine, the distributed-systems theory behind them, and 61 worked case studies that put it all together.
Data Structures & Algorithms
Patterns first, then the problems they unlock.
A practice-driven route through data structures and algorithms. Each lesson teaches a structure or pattern, then works through classic problems with solutions in Python, Java, C++ and Go.
AI Engineering
Building real products on top of foundation models.
How to build and run production AI features as a software engineer: how models behave, calling them reliably, prompts and context, retrieval, agents, evaluation, security, and keeping costs under control.
Machine Learning
From your first model to real-world ML.
A beginner-friendly route through classic machine learning with Python and Scikit-learn. Each part builds a working project using real data, covering regression, classification, clustering, language, time series and reinforcement learning.
Built for actually understanding it
Diagrams everywhere
Architecture and flow diagrams render right in the page, in light or dark mode.
Trade-offs, not just facts
Lessons explain when an approach fits and when it doesn't, with real numbers where they matter.
Track your progress
Mark lessons complete and pick up where you left off. Saved in your browser, no account.
Fast search
Press / anywhere to search all 467 lessons instantly.
Code in four languages
DSA lessons include solutions in Python, Java, C++ and Go.
Popular first lessons
Scalability: Growing a System Without Breaking It
Vertical vs horizontal scaling, stateless services, read vs write scaling, and when scaling is the wrong answer. The vocabulary every system design conversation uses.
17 min readintermediateCaching: From Browser to Database
Cache hierarchy, five write patterns, eviction policies (LRU/TinyLFU), stampede prevention, and why invalidation is the hardest problem in distributed systems.
18 min readintermediateDesign a URL Shortener (TinyURL / bit.ly)
An interview-grade walkthrough for a URL shortener: capacity estimation, short-code generation, hot-key caching, and an analytics pipeline that never blocks the redirect.
20 min readintermediateConsistent Hashing: Keys to Nodes Without Global Reshuffles
The hash ring, virtual nodes, bounded-load variant, rendezvous hashing, Maglev, and jump hash for distributing keys across dynamic node sets.
15 min readFree, open learning for engineers
Engineering Path is a free, independent place to study system design, algorithms, AI engineering and machine learning. The courses build on excellent open-source material, reorganized into a structured path with progress tracking.