Mainmatter head of engineering here. From what we've seen on real projects, I can confirm that asking an AI to migrate the code results at best in somewhat functional but unmaintainable code, and starting from scratch is a better approach… However, starting from scratch doesn't work if the legacy codebase is actively being worked on (eg bux fixes and new features and refactorings) or lacks test coverage and documentation.

Starting from scratch also implies one major release where suddenly it's all Rust (so very risky). In contrast, we found that it's a much smoother transition for end-users and maintainers when we approach large codebases progressively, module by module, while the C engineers continue working on the C code and learn Rust in parallel.

Of course, each migration is different but I wanted to clarify with our field experience.

> would require thousands of changes

But LLMs are great at this, provided you have a test suite to keep the process on the rails.

> there's been a massive increase in people migrating from C to Rust due to LLMs.

Strange. I was expecting the opposite move as LLMs know the C pitfalls and traps well enough to write corrected code.

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Rust is worth learning, but your C skills will continue to be useful for embedded for a long time. Rust support in the embedded world is still growing and you will find yourself going between Rust and C on most projects unless you can carefully pick your platform for Rust support up front.

Coming from C I don’t think you’ll find Rust too foreign, once you internalize how the ownership rules work. In my experience the formal rules of Rust overlap a lot with behaviors that are good practice in C/C++ anyway, but there are some complicated concepts that you need to wrap your head around before expressing them in Rust becomes second nature.

Technically, absolutely.

Whether it would suit you, depends if you can learn to like Rust's approach of moving more work to the type system. In Rust you do certain things the Rust's way, period. Programmers used to C being unopinionated about everything find that objectionable.

Depends exactly what you mean by embedded but Rust isn’t as common as people make it out to be there. In some aread it’s almost entirely unheard of. C will be king for a while yet. There’s a lot of Ada floating around too.

Depends on if your embedded system has a nice toolchain for it and/or how much suffering you are willing to endure. Another consideration is if you have to collaborate with others. Most programmers don't know Rust.

> embedded/systems code?

Depends on platform for embedded. It not very pleasant to write rust if you have to think about binary size. For systems code - sure, use rust.

cheadergen is an open source tool that our Rust lead wrote – not sth. we sell or anything