5 steps
Build an AI ad-copy reviewer in Python
A small Python tool that checks ad headlines against your rules, saves a JSON report, and asks a language model to rewrite the worst one.
Project tutorials
Python AI project tutorials
Build something real, one step at a time. Each program comes from a lesson and has been run, so the code works, and any output shown is what it really prints.
They're all free to read, with no account. A free account adds the exercises, which check your code in the browser. Not sure where to start? See the AI engineer roadmap.
7 steps
How to build an AI agent in Python, from scratch
Build a research agent with tools, an agent loop, citations you can check and an eval, in plain Python with no framework.
6 steps
Cross-entropy loss and KL divergence in Python
Write the loss that language models train on, from scratch with NumPy, along with KL divergence, perplexity and the gradient.
7 steps
Customer churn prediction in Python, step by step
A complete machine learning project with scikit-learn: baselines, a fair model comparison, one honest test, and a decision about who to contact.
7 steps
Train a neural network classifier in PyTorch
Prepare data without leaks, run the checks that catch bugs, train with early stopping, and compare honestly with a simple baseline.
6 steps
Build a GPT from scratch in Python
Write a tiny GPT in PyTorch, train it on a product catalog, and watch it write new descriptions. The whole program is about 70 lines.
7 steps
Fine-tune an LLM and decide whether to ship it
Fine-tune a small chat model, test it on held-back products, and use release gates to catch a candidate that looks better but isn't.
4 steps
Build a command-line app in Python with argparse and SQLite
A complete to-do tool with subcommands, a SQLite database, clear errors and exit codes, using only the standard library.
9 steps
Build a REST API in Python from scratch
Authentication, validation, pagination, idempotency and clean errors, in a working API built with the standard library so you can see how each one works.
6 steps
Build an MCP server in Python from scratch
A working Model Context Protocol server with tools, resources and prompts, written without an SDK so you can see exactly what goes over the wire.
7 steps
Build a coding agent in Python
An agent that reads and edits a project, runs its tests and stops when they pass, with the safety checks that keep it inside the project.
8 steps
Ship a production AI service in Python
API keys, rate limits, validation, caching, model fallbacks, structured logs and an eval, around a service that classifies support tickets.