Learn to code, one tower at a time

Pick a language. Climb its tower floor by floor: short lessons with code you run in the browser, then two real projects on the roof, checked by our corrector.

Own a tower from €35, or subscribe from €3.46 a week.

Open the app Sign up and try one lesson free

One free lesson per account, in the language you choose.

Pay in

Two ways to learn

Own it, forever

Pay once and the tower is yours for life: every lesson, both projects, your certificate and its future updates. Packages and bundles save 15% or more.

€35 per tower, paid once

See the towers

Or subscribe your way

Build a plan from any towers you like. Add more whenever you want, swap a tower once you have finished it, and cancel any time. Your progress is always kept.

From €3.46 a week, billed €15 monthly

Build your plan

How it works

  1. 01

    Five floors per tower, beginner to job-ready. At least 8 hours of lessons.

  2. 02

    Two projects on the roof. You build them at your own pace, in the browser or on your own computer.

  3. 03

    The corrector runs hidden tests and gives you a report card for every requirement.

  4. 04

    Finish both projects and get a certificate for that tower.

Build your own bundle

Any 2 towers

Choose them after you buy — whenever you like

€59

15% off

Buy

Any 4 towers

Choose them after you buy — whenever you like

€119

15% off

Buy

Any 8 towers

Choose them after you buy — whenever you like

€235

15% off

Buy

Any 10 towers

Choose them after you buy — whenever you like

€295

15% off

Buy

The towers

HTML & CSS

  • Build pages with real structure
  • Style with flexbox, grid and themes
  • Make sites fast, accessible and responsive

Portfolio site · Product landing page

€35

Buy See the full tower

JavaScript

  • Logic, data and functions
  • The DOM, events and async
  • Canvas games and real-time

Word-guess game · Arcade game

€35

Buy See the full tower

Python

  • Clean, readable programs
  • Files, errors, classes and tests
  • Automation and command-line tools

Budget manager · Library manager

€35

Buy See the full tower

SQL

  • Ask questions of real data
  • Joins, CTEs and window functions
  • Design, migrate and protect databases

Music-streaming database · Data detective

€35

Buy See the full tower

C++

  • How the machine runs your code
  • Memory, pointers and classes
  • Algorithms, recursion and the STL

Text adventure · Maze generator and solver

€35

Buy See the full tower

Node.js

  • HTTP, servers and APIs
  • Databases, auth and real-time
  • Security, testing and deploying

URL-shortener API · Real-time chat server

€35

Buy See the full tower

Python for Data

  • Clean, question and chart real data with pandas.

Project 1 · Project 2

€35

Buy See the full tower

Flask

  • Build real Python websites and APIs, from first route to logins.

Project 1 · Project 2

€35

Buy See the full tower

Logic & Problem Solving

  • Learn to think like a programmer before, and while, you code.

Project 1 · Project 2

€35

Buy See the full tower

Algorithms & Data Structures

  • Write code that stays fast, and pass the coding interview.

Project 1 · Project 2

€35

Buy See the full tower

Java

  • Core Java from your first class to collections, streams and tests.

Project 1 · Project 2

€35

Buy See the full tower

Machine Learning

  • Teach computers to learn from data, and know when not to trust them.

Project 1 · Project 2

€35

Buy See the full tower

Building with AI

  • Build apps on top of large language models: prompts, tools, search and safety.

Project 1 · Project 2

€35

Buy See the full tower

Everything

Every tower released so far, plus every tower we add later, at 15% off buying them one by one.

€385

Buy

Or build your own monthly plan

Pick any towers. The more you add, the less each one costs. Change or cancel any time; your progress is kept.

Packages

Choose a focused group of towers and save 15%.

Python package

Python · Python for Data · Flask

€105 €89

15% off

Buy

Logical thinking package

Logic & Problem Solving · Algorithms · C++ · Java

€140 €119

15% off

Buy

AI package

Python · Python for Data · Machine Learning · Building with AI

€140 €119

15% off

Buy

Design package

HTML & CSS · UI Design · Tailwind & Sass

€105 €89

15% off

Coming soon

Front-end package

HTML & CSS · JavaScript · TypeScript · React · Tailwind & Sass

€175 €145

15% off

Coming soon

Back-end package

Node.js · SQL · PostgreSQL · TypeScript

€140 €119

15% off

Coming soon

Data package

SQL · PostgreSQL · Python for Data

€105 €89

15% off

Coming soon

Questions

Do I need to install anything?

No. Everything runs in your browser. For the projects you can also work on your own computer and upload your files.

Can I skip what I already know?

Yes. Once you own a tower, each floor has a skip test: score 8 out of 10 and that floor opens.

What is the refund policy?

Refunds within 5 days of purchase. After 5 days, no refunds or returns.

Do I keep access?

Yes. A tower you buy is yours, with no subscription.

Refund policy