Working through a lesson

Every lesson ends with something that runs on your own machine. Work through it in order, run what it asks, then mark it complete.

Find your way

On a computer, the lesson list sits down the left side. It starts with "← Back to course" and how many core lessons you have done. On a phone, open "Lessons" at the top.

The line above the title shows the module and where the lesson sits, such as "Lesson 3 of 20". It counts the same lessons as your progress: the core lessons. An elective shows "Elective" there instead, with no number.

On Starter, the lesson list marks each lesson "Free", "Preview" or "Full course". A "Full course" lesson opens to its title, "Part of the full course" and "Apply for the full course", and nothing else. See Starter: try the course free.

The top of the lesson

• The title, and "Core" or "Elective, not counted". On Starter, the "Free" or "Preview" badge too. An elective also says "Optional: it does not count towards the capstone."
• "About" so many minutes, when the lesson has an estimate.
• "Before this lesson:" lists any lessons to do first, with links.

The parts of a lesson

1. The video, when there is one, above the reading. If it cannot be shown on the page, a "Watch the video" button opens it in a new tab.
2. The reading. Most lessons follow the same order: why it matters, what you will be able to do, what to read or watch at the source, our walkthrough, the exercise ("Do it"), what to watch out for, and where it shows up in the internship.
3. Figures. Simple drawings with a one-line caption under each.
4. "What must run before you continue". A short checklist in a coloured box. Do not move on until each item runs.
5. "Sources". The provider pages the lesson depends on, each with the date someone last checked the lesson against it. Links open in a new tab.

Mark it complete

Press "Mark complete and continue". Your progress moves and the next lesson opens. After your last core lesson, the capstone page opens instead.

A completed lesson shows "Completed". Pressed it by mistake? Press "Undo".

Your progress moves only when you mark a lesson complete. Reading it is not enough.

"Was this clear?"

At the foot of every lesson:

1. Choose "Yes" or "No".
2. Optionally write in "What would make it clearer? (optional)".
3. Press "Send".

Your answer is linked to your account so we can follow up, and you can change it later with "Update my answer". We read every note and use it to fix the lesson.

Ask the AI mentor

Under "Was this clear?" is "Ask the AI mentor". Stuck on the lesson? Type into "Your question" what you ran, what you expected and what happened, and press "Ask". The button reads "The mentor is thinking" while it works. It explains the idea and points at the next step; you write the code.

The line beside the button says how many of today's questions you have left; the count resets at midnight UTC. It is one conversation for the whole course, so your recent questions and replies show under every lesson, and they carry over from Starter to the full course. See The AI mentor chat.

Moving between lessons

The links at the very bottom go to the previous and next lessons. On the last lesson the right-hand link is "Capstone →". On Starter, the next link can lead to a "Full course" lesson, which shows only its title and the way to join.