Learn CodeNotes from sessions with Claude Code, my teacher

Learn Code

A notebook of what we built and why, written after each session with Claude Code. Each lesson explains the ideas in plain English, shows how it was done, what went wrong, and ends with a short quiz and something to try yourself.

  1. 01

    Taming a phone's storage from the command line

    Finding big files, spotting true duplicates with hashes, organising by type, and why "never delete without asking, always keep a backup" became the house rule.

    2026-10-05 · about 3 minutes
  2. 02

    Python and Jupyter on an Android phone

    Installing a modern Python, why virtual environments matter, and the detective story of a Jupyter kernel that kept dying — solved with a tiny C library.

    2026-10-05 · about 3 minutes
  3. 03

    A dashboard that tells the truth

    Building a lottery-results dashboard (HTML + a small Python server + Excel), and why the honest feature — a backtest against random picks — matters more than any "prediction".

    2026-10-06 · about 3 minutes
  4. 04

    Designing with Claude's skills

    How "skills" give Claude a specialist's playbook, and what the canvas-design and frontend-design skills taught us about avoiding generic, AI-looking pages.

    2026-10-06 · about 3 minutes
  5. 05

    Building a RAG from scratch

    How we made an AI assistant that answers only from your own FAQ — embeddings, chunking, cosine similarity, and why it doesn't make things up.

    2026-10-07 · about 6 minutes
  6. 06

    Do you need Supabase? Storing vectors yourself

    Embeddings are just numbers. When a plain file is enough, when a vector database earns its place, and the exact-vs-approximate trade-off.

    2026-10-07 · about 4 minutes
  7. 07

    One builder, many knowledge bases

    Turning PDFs, Word files and web pages into knowledge bases — text extraction, chunking with overlap, exports, and an offline file that works without internet.

    2026-10-07 · about 5 minutes
  8. 08

    Shipping safely to shared hosting

    Uploading over encrypted FTP, password-protecting pages with .htaccess, locking private folders, backing up before every change, and proving it all with tests.

    2026-10-07 · about 5 minutes
  9. 09

    Logins and paid memberships

    How passwords are stored safely, how login tokens work, why Pro checks must happen on the server, Stripe for payments, and designing so you can migrate later.

    2026-10-07 · about 6 minutes
  10. 10

    Working well with Claude Code

    House rules, memory, confirming before acting, backups, and the debugging habits that kept recurring across every project.

    2026-10-07 · about 3 minutes