Databases and SQL
8 lessonsIndex lookup and join97 min
The relational model, SQL from joins to window functions, normalization, transactions, concurrency control, recovery and indexing.
First lesson freeCourses on core CS and the skills around the code
Courses on databases and SQL, operating systems, computer networks and object-oriented programming, plus AI coding agents, UI and UX, learning faster, motivation and getting hired. The first lesson of each course is free.
Core computer science
Operating systems
8 lessonsScheduling and paging119 minProcesses, threads, CPU scheduling, synchronization, deadlocks, paging, virtual memory and file systems, with the numericals exams ask for.
First lesson freeComputer networks
8 lessonsProtocol layers123 minLayering, Ethernet and ARP, IP addressing and subnetting, routing, TCP and its congestion control, DNS, HTTP and TLS.
First lesson freeObject-oriented programming
7 lessonsInterfaces and classes80 minEncapsulation, object lifetime and copying, inheritance and the diamond problem, vtables and dynamic dispatch, abstract classes and interfaces, and composition, in C++, Java and Python.
First lesson free
Skills around the code
AI coding agents
7 lessonsAgent loop81 minHow coding agents work, how MCP connects them to tools, and how to use automated review without shipping its mistakes.
First lesson freeUI and UX for engineers
7 lessonsInterface layers68 minMake interfaces that look deliberate and are easy to use, without a design degree.
First lesson freeLearn hard things faster
7 lessonsSpacing effect · model72 minStudy methods with evidence behind them, applied to algorithms, systems and anything else technical.
First lesson freeMotivation and confidence
7 lessonsTen weeks of practice77 minKeep going when progress is slow, the job market is loud and AI seems to do everything.
First lesson freeGet hired
7 lessonsHiring pipeline80 minFrom your first application to the offer: how hiring works, what to send and how to talk about your work.
First lesson free