Gemini 2.5 Pro vs. Claude 3.7 Sonnet: Coding Comparison

I'd like to see an honest attempt by someone to use one of these SOTA models to code an entire non-trivial app. Not a "vibe coding" flappy bird clone or minimal ioS app (call API to count calories in photo), but something real - say 10K LOC type of complexity, using best practices to give the AI all the context and guidance necessary. I'm not expecting the AI to replace the programmer - just to be a useful productivity tool when we move past demos and function writing to tackling real world projects.

It seems to me that where we are today, AI is only useful for coding for very localized tasks, and even there mostly where it's something commonplace and where the user knows enough to guide the AI when it's failing. I'm not at all convinced it's going to get much better until we have models that can actually learn (vs pre-trained) and are motivated to do so.

I'm at 3k LOC on a current Rust project I'm mostly vibe coding with my very limited free time. Will share when I hit 10k :)

Would you mind sharing what the project is, and which AI you are using? No sign so far of AI's usefulness slowing down as the complexity increases?

>Would you mind sharing what the project is

rust + wasm simulation of organisms in an ecosystem, with evolving neural networks and genes. super fun to build and watch.

>which AI you are using?

using chatgpt/claude/gemini with a custom tool i built similar to aider / claude code, except it's very interactive, like chatting with the AI as it suggests changes that I approve/decline.

>No sign so far of AI's usefulness slowing down as the complexity increases?

The AI is not perfect, there are some cases where it is unable so solve a challenging issue and i must help it solve the issue. this usually happens for big sweeping changes that touch all over the codebase. It introduces bugs, but it can also debug them easily, especially with the increased compile-time checking in rust. runtime bugs are harder, because i have to tell the ai the behavior i observe. iterating on UI design is clumsy and it's often faster for me to just iterate by making changes myself instead.

Thanks - sounds like a fun project!

Given that you've built your own coding tool, I assume this is as much about testing what AI can do as it is about the project itself? Is it a clear win as far as productivity goes?