Vibe coding for beginners: how to start, and how to keep the demo standing

Vibe coding means building software by describing what you want to an AI coding assistant and letting it write most of the code. To start, pick a project small enough to finish in a day or a weekend, build it in short loops of request, run and check, and test it hard before anyone else sees it. The describing is easy. The checking is the skill.

What is vibe coding good for, and where does it break?

Vibe coding is a quick way to get from an idea to a working prototype. It lowers the barrier for designers, founders and students who know what they want but not every line of syntax. Experienced developers can use it to skip repetitive setup work.

It also has weak spots you should plan for. An AI coding assistant can produce code that looks right but fails on inputs you did not try. It may add libraries you do not need, change files you did not ask about or put secrets directly in the code. On a larger project, you may find it loses track of earlier decisions. None of this means you should avoid it. It means you need a small scope and a habit of checking.

How do you pick a project small enough?

A good first project has one user, one main action and one result. If you cannot describe it in a sentence, it is too big.

Too big	Right size
An AI tutor for every school subject	A page that turns a pasted paragraph into five quiz questions
A full personal finance app	A tool that sorts a pasted list of expenses into categories
A social network for builders	A form that drafts a project description from three short answers

Write down what "done" looks like before you start. For example: "I paste text, click a button, and see five questions with answers within a few seconds." That sentence is your target and your test.

How do you write the first request?

Your first message to the assistant sets the shape of the whole project. Include:

• What it does, in one or two sentences, with the user in it.
• The stack, if you have a preference, or ask the assistant to suggest a simple one and explain why.
• The scope limits: single page, no login, no database unless needed.
• How it should handle secrets: API keys in environment variables, never in the code.
• What to return: the files, plus short instructions for running it locally.

Then ask it to build only the first working version. Resist asking for everything at once.

How do you build in small loops?

Work in loops of one change at a time.

1. Ask for one change, such as "add a loading state while the request runs."
2. Run the app and try the change yourself.
3. If it works, save a commit with a short message. If it breaks, describe the exact error or behavior and ask for a fix.
4. Repeat.

Commit after every working change. If the assistant takes a wrong turn, you can go back to the last good version instead of untangling a broken one. Read each change before you accept it, even briefly. You are looking for surprises: deleted code, new dependencies or files you did not expect to change.

If a long conversation starts to drift and the assistant ignores earlier decisions, try starting a fresh session. Paste in a short summary of the project and its current state, then carry on.

How do you check the output so the demo holds up?

Assume the first person to try your demo will do the thing you did not plan for. Do it yourself first. Before you demo, run through this checklist:

• Fresh start: clone the repository into a new folder and follow your own README. Does it run?
• Empty and odd input: submit nothing, very long text, another language or special characters.
• Slow or failed AI calls: what does the user see if the model API is slow or returns an error?
• No secrets in the repo: search for keys and tokens before you push. API keys should never be committed.
• Explain it: can you say what each main file does? If not, ask the assistant to explain, and read the code until you can.
• Backup: record a short screen capture of the working flow in case the live demo or the network fails.
• Honest scope: know which parts are real and which are placeholders, and say so if asked.

The "explain it" item is the one we would put first. Anyone reviewing your project may ask how it works. "The assistant wrote it" is not an answer, but "I asked for X, checked Y and changed Z" is.

Can you vibe code at a hackathon?

Before you rely on an AI coding assistant at any event, read that event's rules, and follow them. If something is unclear, ask the organisers before you start rather than after you submit. Either way, it is good practice to note in your README how you used AI tools, so reviewers can see what you built and what you checked.

If you already work with an AI agent, you can bring it along: Starfield Labs has an MCP connection for agents.

Where to go next

Pick a right-size project from the table above and build it this week. Then put the method under real pressure: find a hackathon at starfieldlabs.ai/events and use the checklist before your demo. For step-by-step builds you can adapt, see the tutorials at starfieldlabs.ai/tutorials.