Courses for the 10 most-used languages and frameworks

10 courses

• • Web

  JavaScript

  A practical JavaScript course from a first program in the console to async code, Web Workers, security and publishing a package. Every example is run and checked against ECMAScript 2026.

  Beginner to advanced, three levels

  91 lessons · about 47 h

  61 of 91 lessons written so far

  61 of 91 lessons written so far

  Before you start

  Helpful first: HTML & CSS

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 66% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Data
  • Backend

  SQL

  A practical SQL course on PostgreSQL, from creating a first table to tuning queries, securing data and keeping a database healthy. Every query is run and checked on PostgreSQL 18.

  Beginner to advanced, three levels

  60 lessons · about 27 h

  20 of 60 lessons written so far

  20 of 60 lessons written so far

  Before you start

  No prerequisites

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 58.6% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Backend
  • Data

  Python

  A practical Python course from installing Python to typing, concurrency and publishing a package. Every example is run and checked against Python 3.14.

  Beginner to advanced, three levels

  82 lessons · about 43 h

  82 of 82 lessons written so far

  82 of 82 lessons written so far

  Before you start

  No prerequisites

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 57.9% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Web
  • Backend

  TypeScript

  A practical TypeScript course from a first compiler error to generics, type-level programming, declaration files and large projects. Every example is compiled and checked against TypeScript 7.0.

  Beginner to advanced, three levels

  81 lessons · about 37 h

  25 of 81 lessons written so far

  25 of 81 lessons written so far

  Before you start

  Requires: JavaScript

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 43.6% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Backend

  Java

  A practical Java course from a first program in JShell to generics, streams, concurrency and shipping a runtime image. Every example is run and checked on Java 25, the current long-term support release.

  Beginner to advanced, three levels

  77 lessons · about 32 h

  0 of 77 lessons written so far

  0 of 77 lessons written so far

  Before you start

  No prerequisites

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 29.4% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Backend

  C#

  A practical C# course from a first single-file program to LINQ, asynchronous code, dependency injection and shipping a native tool. Every example is run and checked on C# 14 and .NET 10.

  Beginner to advanced, three levels

  72 lessons · about 30 h

  0 of 72 lessons written so far

  0 of 72 lessons written so far

  Before you start

  No prerequisites

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 27.8% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Systems

  C++

  A practical modern C++ course from a first compiled program to ownership, move semantics, templates, concurrency and performance. Every example is compiled and run as C++23 with sanitizers switched on.

  Beginner to advanced, three levels

  84 lessons · about 35 h

  0 of 84 lessons written so far

  0 of 84 lessons written so far

  Before you start

  No prerequisites

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 23.5% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Backend

  Node.js

  A practical Node.js course from a first script and project setup to HTTP APIs, streams, testing, performance and security. Every example is run on the current LTS release.

  Beginner to advanced, three levels

  77 lessons · about 36 h

  25 of 77 lessons written so far

  25 of 77 lessons written so far

  Before you start

  Requires: JavaScript · Helpful first: Bash and the Linux shell and PowerShell

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 48.7% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Web

  React

  A practical React course from a first component to reducers, effects, forms with Actions, Suspense and Server Components. Every example is run and checked against React 19.3.

  Beginner to advanced, three levels

  79 lessons · about 36 h

  27 of 79 lessons written so far

  27 of 79 lessons written so far

  Before you start

  Requires: JavaScript · Helpful first: HTML & CSS and TypeScript

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 44.7% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course
• • Web

  Next.js

  A practical Next.js course from a first App Router app to Server Components, data mutations, caching, security and deployment. Every example is built and checked against Next.js 16.3.

  Beginner to advanced, three levels

  75 lessons · about 31 h

  0 of 75 lessons written so far

  0 of 75 lessons written so far

  Before you start

  Requires: React · Helpful first: TypeScript

  Stack Overflow — 2025 Developer Survey: Technology

  Used by 20.8% of survey respondents (Stack Overflow — 2025 Developer Survey: Technology)

  View the course