I’m Thijs, new to the community and excited (and a bit nervous) to share what I’ve been working on: it's called Prototyper.

The motivation: I was curious how much more "taste" you could get out of an LLM if you built the entire infra yourself: tool calling, code execution, rendering—instead of layering on top of existing stacks. Over the past year I built a custom compiler, runtime, and design engine from scratch to see if this could make LLM-driven design genuinely better.

A few details:

- Own compiler + code runtime → no shadcn, no third-party UI kit, no external execution layer.

- Instant feedback (no compile/refresh lag).

- Deterministic design controls that integrate with llm-generated code.

Because we control the full stack, we can try things that I haven’t seen elsewhere, like inference tightly coupled with live code execution, or new approaches to integrating design controls with llm generated code.

It’s still early, and I’d love feedback from the HN community: is this approach actually better than what’s out there today? Everyone gets a free week to try it.

Happy to dive into the tech in the comments! :)

—Thijs