It can’t write a single document correctly. I asked it to write the API documentation for the interpreter I’m building. It invented functions that don’t exist and got all the parameter lists wrong. Functions like `shouldClose`, `swapBuffers`, `pollEvents`, `terminate` aren’t even in my interpreter, yet it put them in the docs and got every parameter wrong.
2. It’s great at creating duplicate functions
In C, duplicate function names won’t compile, but it seems to create duplicates about 60% of the time. It even creates duplicate `case` labels in `switch` statements. It often produces identical code under different names.
3. It’s excellent at producing bugs
It creates `struct`s, initializes them, assigns values, then when asked to initialize and run or to implement SSR reflection it sets the alpha to full so the entire GLB becomes transparent, or when asked to make a glass material it just makes it opaque (I tried 15 times and gave up). They claim it’s at a professional engineer level—what, kindergarten-level engineers?
4. It never gives code that actually works
Even code to read a single file is a bug-ridden mess; it’s faster to implement it yourself.
It does null checks here and there, but maybe it should check other things first instead of spending time on those.
5. Serious memory leaks
It generates code with memory leaks. Using Claude Opus 4.5 made me so frustrated that I wrote a lot of profanity into my prompts.
6. It adds things I didn’t ask for
It adds noise to shadows claiming it looks more natural, but it just looks dirty. I’ve even seen it “fix” reflections by placing a white plane on the floor and calling that light reflection.
7. Mozart’s Dice–level composition
Good luck getting solid code—everything is a defective, patchy mess.
8. As long as it doesn't crash, that's all that matters
If a function is supposed to return a float, just compare it as an int—so change the function's return type to int! Claude Opus 4.5 is truly amazing! It’ll probably reach AGI soon!