[b4ckup]

I'd say on average about 50% faster but it really depends on the task at hand. On problems that can be isolated pretty well like a new feature that is relatively isolated (for example building a file export in a specific format) it's easily a 10x speed up. One thing that generally gets less talked about is exploration of the solution space during manual implementation. I work in a very small company and we build a custom ERP solution. Our development process is very stripped down (a good thing IMO). Often times when we get new requirements we brain storm and make a rough design. Then I try implement it and during that phase new questions and edge cases arise, and at any time this happens we adjust the design. In my opinion this is very productive as the details of the design are worked out when I already know the related code very well as I already got down to implementing. This leads to a better fitting design and implementation. Unfortunately this exploration workflow is incompatible with llms if you use them to do the implementation for you. Which means that you have put more effort in the design up front. From my experience that means the gain in speed in such task is nullified and also results in code that fits worse into the rest of the codebase.