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My dad vibe-coded a thermostat UI in 12 hours

Written by Juri Mlich on 2026-03-21. AI only fixed typos

My dad is a tinkerer. He’s got a 3D printer, a CNC cutting machine, something to do with lasers, he’s good with electricity, … the whole deal. For the past year and a half, I’ve been helping him with code. It’s not easy for him, especially considering almost all great resources are in English, not in our native language (Slovak). So every time I’d come home for a visit, there’d be a “come have a look, how do I do x” kind of question.

I would always have to do a tiny calculation in my head: “The right way to do this would be x, but then he’d need to learn y and for his needs that’s too complicated… so the easiest would be to do z… but I don’t want to just tell him what to type so how do I explain it in an easy way so that the next time he finds himself with a similar problem, he can do it on his own?”

Last week, however, I got a brilliant idea - I’ll set up Claude Code for him. The UI wouldn’t be in Slovak but I’d write a CLAUDE.md instructing it to always speak to him in Slovak. And let me tell you - for his needs, it’s flawlessly perfect. He doesn’t have projects with hundreds of thousands of lines of code deployed on a hyperscaler. His needs are simple. So I set it all up for him, explained what the command line is, how to cd into the right directory, taught him the basics of git (just enough to save his work), wrote a simple global CLAUDE.md, had him use it for a few smaller things while giving him hints and let him work.

Now, a week later, I woke up to a flood of messages from him. Apparently he’s been vibe coding for the last 12 hours and managed to get done what he thought would take him half a year. He coded a UI for his homemade thermostat (they live in the countryside, so they burn wood and coal and have some solar panels) and made it available as a website on his home network.

WhatsApp messages from my dad about the thermostat The physical thermostat display

I’m honestly so excited for him! So to all the programmers out there with tinkerer dads - set up Claude Code for them. You don’t know what might happen.

(But please educate them on security. Tell them to never expose anything to the public network. Tell them they might have bugs so to absolutely make sure there’s no way the program can burn their house down, etc.)

Here’s the CLAUDE.md I wrote for him (translated to English):

## Who I am
A beginner programmer. I know the basics, but I need clear explanations.

## How to communicate
- Respond in Slovak
- Explain simply, without unnecessary jargon
- If you use a technical term, explain it in parentheses
- When you suggest something, explain WHY, not just WHAT

## Language barrier
- I don't speak English
- Terminal commands are in English – always translate/explain them in Slovak
- Before running any command, show it, translate what it does, and wait for confirmation
- Write git messages (commit messages) in Slovak. If I say something about saving changes, I'm referring to git (I don't know how git works under the hood)
- If an English error message appears, first translate it and then explain what happened and how to fix it

## Code
- Prefer simpler solutions over "elegant" ones
- Don't add unnecessary comments to the code
- If I'm modifying an existing file, show exactly what to change and where
- Before running destructive commands (rm, DROP, reset), ask first

## When I'm not sure
- If I ask something vague, ask back rather than guess
- If there are multiple approaches, suggest the simplest one and only explain alternatives if I ask

## Security
- Never store passwords or tokens directly in the code
- Warn me if I'm doing something potentially dangerous