Programming
From Python syntax to React hooks to production databases — test your coding knowledge across the languages and tools developers use every day.
General
Broad-strokes basics across the most common languages and tools.
Python Basics Quiz
Test your understanding of Python syntax, data types, and core concepts.
JavaScript Fundamentals Quiz
Test your knowledge of JavaScript variables, functions, and core language features.
HTML & CSS Basics Quiz
Test your knowledge of HTML structure and CSS styling fundamentals.
SQL Basics Quiz
Test your knowledge of SQL queries, joins, and database fundamentals.
Git Commands Quiz
Test your knowledge of Git version control commands and workflows.
Python
Data structures, functions, OOP, and the Python web frameworks.
Python: Data Structures
Lists, tuples, sets, dicts, and when to use each one.
Python: Functions & Decorators
args, kwargs, closures, lambdas, and the magic of decorators.
Python: Object-Oriented Programming
Classes, inheritance, encapsulation, and Python's OOP model.
Python: File I/O
Reading, writing, and managing files safely in Python.
Python: List Comprehensions
Write cleaner, faster list-building code with comprehensions.
Python: Regular Expressions
Pattern matching, metacharacters, and the re module in Python.
Python: Virtual Environments & pip
Isolate dependencies and manage packages like a professional.
Python: Django Basics
Models, views, URLs, and the MTV pattern in Django.
Python: Flask Basics
Routes, templates, and request handling in Flask.
JavaScript
Core language features, TypeScript, and React — from ES6+ syntax to hooks.
JavaScript: ES6+ Features
Arrow functions, destructuring, spread/rest, template literals, and classes.
JavaScript: Promises & Async/Await
Promise states, chaining, and async/await error handling.
JavaScript: DOM Manipulation
Selecting elements, changing content, and handling events.
JavaScript: Closures & Scope
Lexical scope, hoisting, the TDZ, and classic closure gotchas.
JavaScript: Array Methods
map, filter, reduce, and which methods mutate the original array.
JavaScript: TypeScript Basics
Type annotations, primitive types, and compiling with tsc.
JavaScript: TypeScript Interfaces & Generics
Interfaces, generic functions and classes, and type constraints.
JavaScript: React Fundamentals
JSX, components, props, and the Virtual DOM.
JavaScript: React Hooks
useState, useEffect, custom hooks, and the rules of hooks.
JavaScript: Node.js Basics
Modules, the fs module, npm, and building a basic HTTP server.
Web
Layout, protocols, APIs, and the auth mechanisms that hold the web together.
Web: CSS Flexbox
justify-content, align-items, flex-grow, and wrapping behavior.
Web: CSS Grid
Grid tracks, the fr unit, minmax(), and item placement.
Web: CSS Animations & Transitions
Transitions vs. keyframe animations, timing, and easing.
Web: Responsive Web Design
Viewport meta tag, media queries, and mobile-first design.
Web: REST API Design
HTTP methods, status codes, idempotency, and URL structure.
Web: HTTP & HTTPS
Default ports, SSL/TLS, certificates, and MITM attacks.
Web: Web Security Basics (OWASP Top 10)
SQL injection, XSS, CSRF, and the risks OWASP tracks.
Web: JWT Authentication
Token structure, expiration, storage, and signing algorithms.
Web: OAuth 2.0
Roles, the Authorization Code flow, tokens, and PKCE.
Databases & DevOps
Databases, containers, the command line, and the pipelines that ship it all.
Databases & DevOps: MongoDB Basics
Documents, collections, query operators, and aggregation.
Databases & DevOps: Redis Basics
Key-value model, data structures, persistence, and TTL.
Databases & DevOps: Docker Basics
Images vs. containers, Dockerfiles, and docker-compose.
Databases & DevOps: Linux Command Line
grep, process management, file permissions, and piping.
Databases & DevOps: Bash Scripting
Variables, conditionals, redirection, and cron scheduling.
Databases & DevOps: PostgreSQL Advanced Queries
Window functions, CTEs, JSON operators, and query tuning.
Databases & DevOps: CI/CD Concepts
CI vs. CD, blue-green deploys, canary releases, and IaC.
Databases & DevOps: Git Advanced (rebase, stash, cherry-pick)
Interactive rebase, stash internals, and cherry-pick use cases.
CS Fundamentals
The core CS concepts behind every codebase — data structures, algorithms, and design.
CS Fundamentals: Arrays & Linked Lists
O(1) access vs. O(n) insertion — the classic trade-off between the two most basic data structures.
CS Fundamentals: Stacks & Queues
LIFO vs. FIFO — push, pop, enqueue, dequeue, and where each one actually gets used.
CS Fundamentals: Trees & Graphs
DFS, BFS, spanning trees — navigating the structures behind most non-linear data.
CS Fundamentals: Big O Notation
O(1), O(n), O(log n), O(n²) — measuring how an algorithm scales.
CS Fundamentals: Sorting Algorithms
Bubble sort, merge sort, quicksort — comparing how different algorithms put things in order.
CS Fundamentals: Binary Search
O(log n) — finding a value fast by cutting the search space in half every time.
CS Fundamentals: OOP Principles
Encapsulation, inheritance, polymorphism, abstraction — the four pillars of object-oriented code.
CS Fundamentals: SOLID Principles
Single responsibility, open/closed, Liskov substitution — the five rules for maintainable OOP design.
CS Fundamentals: Design Patterns (GoF)
Singleton, Factory, Observer, Strategy — the classic reusable solutions to recurring design problems.
CS Fundamentals: Unit Testing Basics
Assertions, mocks, test coverage — the fundamentals of testing code in isolation.
CS Fundamentals: Regular Expressions
\d+, .*, [a-z]+ — the pattern-matching language every programmer eventually needs.
CS Fundamentals: Computer Networks Basics
TCP/IP, DNS, HTTP — how data actually gets from one computer to another.