This morning I set out to make an Elixir library for internal use of some specific statistical method that only seemed to exist in some Python code. Said method is processing intensive, and I prefer not Python, so aiming for an Elixir library instead with Rust for the processing heavy stuff.
So the prompt went something like: I want a best practice Elixir library for XXX with Rust doing the heavy processing and a Rustler NIF in between. Make a plan to research this method and its algorithms, make tests including mocking end-to-end with known expected results, and use relevant skills for both planning and implementation. After passing tests run code quality checks set on strict and fix any issues. Then write an API user guide.
A bit over an hour later I had it complete with passing tests, code quality checks and results that matched the Python version across all relevant tests - just faster and now through an Elixir API.
Then I figured it might be even faster using the GPU for some bits. So I asked Claude to use OpenCL to move some of the suited processing heavy parts over there. Less than an hour later those parts were running correctly on the GPU instead. (And a lot of that time was about getting a OpenCL setup working for Intels built-in laptop graphics).
I’ve seen talk about reports saying we just feel more productive using AI coding, but that we’re actually less so. That is not my experience, and I don’t think I’ve fooled myself either. For instance I just can’t see any part of this where I would have done better without AI.
This was just about 4000 lines code across Elixir, Rust and OpenCL. Larger codebases which doesn’t fit properly in the context have more issues. But still - I’m pretty sure I’m more productive, and by fairly big leap.
Edit: Fixed some typos. And after benchmarking the Elixir/ Rust version is between 10x to 30x faster, and the GPU version ever so slightly faster than that again. (A discrete GPU will make real a difference).






















