This is where I've landed too, I imagine based off all the responses that it depends on domain and also the rigor you care about in your implementation. For me, what I do, and the quality required, there's just not much time (if any) saved on handing off the implementation to an LLM.

But that doesn't mean they're useless either. I use them all the time for review as you mentioned or to knock out one-off scripts that don't go anywhere near source control. There's just no world where I don't need to understand every line of code that I'm responsible for getting into our project.

This is my eternal battle as a perf engineer. Performance starts with architecture and you can only squeeze so much out a hotpath with poor data layout.

The nice part is that data-oriented code almost always easily supports threading and SIMD.

On the flip side a lot of my work as a performance engineer is undoing bad abstractions made by people who read a two blog posts about SoA and decide that encapsulation is stupid