Learn to build
real software.
Free, in-depth lessons on frontend, Go, Node.js, Python, Rust, SQL, system design, security and AI engineering. Each one comes with worked examples, a practice task and a quiz, so you know you've got it before moving on.
Free · no account needed · sign in to save progress and use the tutor
- roadmaps
- 13
- complete lessons
- 196
- interactive labs
- 19
- quiz questions
- 784
Why LevelCode
Stop collecting tabs. Start finishing topics.
Lessons, not link lists
Each node is a complete chapter written to be read start to finish: explanations, step-through diagrams, interactive simulations and runnable examples.
Practice, then prove it
A hands-on task with a hidden solution and a short quiz with explanations for every answer.
A tutor with context
Ask about any paragraph. The tutor sees the lesson you are on, so answers use the same terms and examples.
Progress that follows you
Mark lessons as in progress, done or skipped. Your map fills in as you go and syncs to your account.
Pick a path
Every roadmap is a full course.
Role-based roadmaps
Everything a job title expects of you, in order — from first principles to production.
Software Engineer
Fundamentals, both sides of the stack, software design — and the interviews that get you hired.
Frontend Developer
From your first HTML tag to shipping fast, accessible React apps.
Backend with Go
Design, build and ship production HTTP services in Go.
Backend with Node.js
Build production APIs in TypeScript on Node.js, from the event loop to deployment.
Full-Stack Developer
Own a feature end to end: React in the browser, Node and PostgreSQL behind it, shipped as one.
AI Engineer
Build reliable products on top of large language models.
DevSecOps Engineer
Build security into every stage of how software is built and shipped.
Skill-based roadmaps
Go deep on one technology. Role roadmaps embed these where they fit.
Learn to Code
Never programmed before? Start here and write real programs in Python.
Python
From scripts to typed, tested, production Python: packages, async and web APIs.
SQL & Databases
Query, model and tune relational databases with confidence.
System Design
Design systems that scale, stay correct and survive failure.
Rust
Memory safety without a garbage collector — and the mental model that makes the compiler your ally.
Git & Collaboration
Version control you actually understand — not just memorized commands.
Labs
Don't just read it. Poke at it.
The simulations from the lessons, each on its own page: step through the event loop, run joins, rebase a branch, sample tokens, evaluate an IAM policy. Every lab links back to the lesson that explains it.
Browse all 19 labs- Box modelChange padding, border, margin and box-sizing and watch the rendered size of an element change.
- Flexbox playgroundFlip direction, justify, align and wrap on a live flex container until the axes make sense.
- Event loopStep through the call stack, microtasks and tasks to see exactly when each callback runs.
- Go channelsSend, receive and close on buffered and unbuffered channels and see who blocks, and when.
- SQL joinsRun INNER, LEFT, RIGHT, FULL and CROSS joins on the same two tables and compare the rows.
- Index vs sequential scanCount the pages a sequential scan and a B-tree index lookup read to find one row.
- Git graphType real Git commands and watch commits, branches and HEAD move on a live commit graph.
- TokenizerSplit text into tokens with a toy vocabulary and see why code and rare words cost more.
FAQ
Questions before you start.
Where should I start?
Never programmed before: start with Learn to Code, which teaches the basics in Python. Want the all-round path — fundamentals, both sides of the stack, software design and interview prep: Software Engineer. New to building for the web: start Frontend Developer at "How the web works". Want to write servers: Backend with Go, or Backend with Node.js if you would rather use TypeScript. Want to own features end to end: Full-Stack Developer. Already shipping software and adding LLM features: AI Engineer. Moving into security or infrastructure: DevSecOps Engineer. Learning a language in depth: the Python and Rust roadmaps. SQL & Databases, System Design and Git & Collaboration stand alone, and the role roadmaps include them where they fit.
Is LevelCode free?
Yes. Every lesson, quiz and lab is free to use without an account. A free account syncs your progress across devices and unlocks the AI tutor with a monthly token allowance.
What is in a lesson?
A complete chapter of roughly 15 to 20 minutes: explanations, worked code examples, diagrams or an interactive simulation where they help, a practice task with a hidden solution, key takeaways and a four-question quiz that explains every answer.
How does the AI tutor work?
Open it on any lesson or select a passage and ask. The tutor has read that lesson and the roadmap it belongs to, so answers use the same terms and examples. It needs a free account; each month you get a token allowance, and your account page shows how much is left.
Do I have to follow the order?
No. Stages are ordered from foundations to production, but you can open any lesson, mark steps as skipped, and leave optional steps for later. At "pick one" steps you choose the option that fits your stack. Progress on an embedded roadmap such as Git counts everywhere it appears.
Is my progress saved without an account?
Yes, in this browser. When you sign up, that progress is merged into your account and follows you to other devices.
Your next lesson is one click away.
Create a free account to sync progress across devices and get a monthly allowance of AI tutor tokens.