I disagree - having worked on backends most of the time, I find modern frontend much more complex (and difficult to test) than pure backend. When I say modern frontend - its mostly React, state management like Redux, Zustand, Router framework like React Router, a CSS framework like Tailwind and component framework like Shadcn. Not to mention different versions of React, different ways of managing state, animation/transitions etc. And on top of that the ever increasing complex quirks in the codebase still needed to be compatible with all the modern browsers and device sizes/orientation out there.

Isn’t frontend more complex? If my task starts with a Figma UI design, how well does a code agent do at generating working code that looks right, and iterate on it (presuming some browser MCP)? Some automated tests seem enough for an genetic loop on backend.

Training data is quite readily available as well, and the online education for React is immense in volume. Where enterprise backend software tends to be closed source and unavailable, and there's much less good advice online for how to build with say Java or .NET

That said, I still get surprising results from time to time, it just takes a lot more curation and handholding.

Or perhaps the sort of things it's been trained on? There's not really a huge corpus of material re: beating Pokemon in the manner it has to play Pokemon, especially compared to the mountains of code these models have access to.