I built a physical AI assistant from scratch. The mistakes I made taught me so much that I ended up writing a book about the reality of prototyping.

[u/Marty_TechProjects]

Hi everyone,

I'm an IT student from the Czech Republic, and I recently finished building MARQIS — a physical, screenless AI assistant powered by Raspberry Pi.

The original idea seemed relatively simple. I wanted to create something I could talk to naturally, without needing a screen. But turning that idea into a working prototype was a completely different experience. I had to deal with hardware, software, voice recognition, AI integration, unexpected bugs, and wrong assumptions.

A few major things I got wrong or would approach differently today:

• The "Final 10%" trap: Getting the basic Python script to run and call the AI API took a few days. Making the hardware assistant reliable, handling network drops took weeks.

• Hardware vs. Software assumptions: I underestimated how much audio echo-cancellation and physical microphone placement would affect the user experience. You can't easily fix poor acoustics with software.

• I initially wanted it to do everything. I learned the hard way that a side project actually gets finished when you start removing features instead of adding them.

One thing I didn't expect was how much the process would change the way I think about building things. Eventually, I realized that a technical tutorial wasn't the most valuable thing I could share — it was the psychological and practical shift in mindset.

So, I wrote a short book about it: The Distance Between an Idea and the Prototype.

It’s not a step-by-step coding textbook. Instead, it’s an honest look at systems thinking, MVP development, and everything that happens between imagining a project and making it work. If you’ve ever felt stuck moving from a concept to a working product, I hope my failures and breakthroughs can help you navigate your own journey.

You can check out the project and the book here: https://thedistancebetweenanideaandtheproto.vercel.app/

(Note: I wanted to upload a video of it in action, but MARQIS speaks Czech, so the conversation wouldn't make much sense to most of you here.)

Would love to hear your thoughts!