You will work with a coding agent during your entire trainee program. The agent explains concepts, helps you when you are stuck, reviews your code and — later in the program — writes code under your direction. This card shows you the tool, our rules for using it, and gets your laptop set up.

Important

Work on this lesson in teacher mode.

Learning goals

• You can start Claude Code, work in a session, and resume it later.
• You can explain the usage quota and which model to work on.
• You can explain our session modes (teacher,...

Introductory Ruby practice for reading and writing simple programs, with focus on data types, control flow, methods, classes, error handling, blocks, and regular expressions.

Finding the right API reference is fragmented across Ruby, Rails, gems, web platform docs, and external SaaS sites. Bookmarks and search profiles make everyday lookups faster.

Git is the version control system for tracking changes, branching, merging, and syncing code between local repositories and servers.

Managing Ruby, Rails and gem versions across many projects requires Bundler and rbenv to keep environments consistent and switch versions safely.

HTML describes what is on a web page: headings, paragraphs, lists, links, images and forms. Everything you build from here on attaches to it — Rails renders HTML, your CSS selects it, your JavaScript walks it.

Important

Work on this lesson in teacher mode.

Note

Many trainees arrive already knowing HTML. If that is you, read the learning goals, confirm you could do the exercises, and move on to the next card. This card exists so that nobody has to pick HTML up by guessing.

Learning goals

• You can write a complete HTML do...

Ruby on Rails basics for building CRUD apps with ActiveRecord, routes, controllers, views, validations, migrations, and associations.

At makandra you will constantly work in applications you didn't write: customer projects, legacy apps, gems. A coding agent can read a code base much faster than you and explain it to you. This lesson teaches you to ask the right questions, and to check the answers, because an agent's explanation is a hypothesis, not a fact.

Important

Work on this lesson in teacher mode.

Learning goals

• You can ask an agent about an unknown code base in a way that gets useful answers: an overview first, then narrower questions.
• You can trace...

Test basics for Rails focus on unit and end-to-end coverage, Capybara browser control, and choosing the right test level without overtesting.

Factories keep test data isolated and predictable in Rails, replacing fragile fixtures with explicit records and reusable defaults for unit and feature tests.

Rails model validations prevent incomplete or invalid movie data from being saved, with field-specific errors and flash feedback on failed forms.

CSS fundamentals for styling and layout: selectors, box model, inline vs. block, Flexbox, Grid, DevTools inspection, and Sass basics.

Core JavaScript language concepts for browser-side logic: variables, functions, control flow, arrays, errors, and the tricky behavior of this and callbacks.

JavaScript can manipulate the browser DOM to add interactivity: select elements, register events, change classes and attributes, and apply the same change to many nodes.

Learn Haml syntax for reading and writing templates, including attribute formats and silent Ruby lines for code that should not render to HTML.

ActiveRecord scopes keep large record sets in the database, reduce Ruby object churn, and help avoid N+1 queries by chaining filters, preloading, and plucking.

Principles for maintainable Rails and object-oriented code: reduce duplication, keep responsibilities narrow, and separate search from authorization to simplify public APIs.

Repeated Ruby calculations and HTTP requests waste time; memoization caches results for fast reuse with @variable ||= computation or the memoized gem.

Breakpoints and browser tools help locate the exact line or interaction where behavior diverges from expectations, inspect state, and continue execution safely.

RSpec matcher design, DRY specs, mocking, and Rails request and helper specs for testing callbacks, changelogs, redirects, and error handling.

Developers need a simple system to capture tasks, plan first steps, manage email, and reduce distractions so work does not get lost or pile up.

makandra’s development workflow for issues, reviews, merges, and production deploys balances traceability with lightweight project management.

Linux command-line essentials for everyday file, process, package, SSH, and shell tasks, plus editor setup, shortcuts, permissions, and executable scripts.