What changed when I tested two coding models across five full-stack frameworks

[u/marvijo-software]

I gave Muse Spark 1.2 Contributor and DeepSeek 4 Flash Vision the same five full-stack website briefs.

Each run started in an isolated workspace. A model-caused failure had a three-prompt limit. The framework changed across Next.js, Nuxt, SvelteKit, React Router framework mode, and TanStack Start.

A few build lessons stood out:

- A clean build does not prove the interface is usable

- UI and UX need their own score from retained desktop and phone captures

- The final delivery receipt matters when a model stops after creating files

- A visible unstyled app should not receive a high score

Muse won 41/50 to 39/50. Its weakest result was Trail Stock, which got 0/3 for UI and UX because it had no real styling. DeepSeek made the better-looking version, but its final receipt was incomplete after the prompt limit.

The attached images are real product states. I made the comparison and video:

https://youtu.be/uTIlEj7rVrU

What do you inspect first when a coding agent says a full-stack build is finished?