6 courses

Learn

The basics, written so you can check them. Every claim a lesson makes is either a definition or an example you can run here, on real infrastructure, and see the output of.

SQL
7 lessons · 46 min
The language every backend job assumes you already know, from SELECT to the joins people get wrong in interviews.
Start the course
TypeScript
6 lessons · 39 min
Types on top of JavaScript, from annotations to the narrowing that makes the compiler useful rather than noisy.
Start the course
JavaScript
5 lessons · 38 min
The language every frontend and Node job assumes you already know — values, functions, this, and the async model that trips almost everyone up once.
Start the course
Python
5 lessons · 37 min
The basics behind the syntax — mutability, scope, comprehensions, and the object model — not just how to write a for loop.
Start the course
Java
5 lessons · 39 min
Classes, collections, interfaces and exceptions — the object model an interview actually probes, with the mistakes almost everyone makes once.
Start the course
C#
5 lessons · 37 min
Value types against reference types, collections, interfaces and LINQ — the fundamentals behind every .NET job posting.
Start the course

Learn

SQLSQL

TSTypeScript

JSJavaScript

PyPython

JavaJava

C#C#

SQL

TypeScript

JavaScript

Python

Java

C#