There isn't any one single thing. CodePerfect gets its speed largely by declining to copy all the extreme bloat that makes the modern tech stack slow. In particular, we:

1. Use a low level language (C/C++) and render our own UI with OpenGL.
2. Eschew large dependencies like Electron, language servers, etc.
3. Write simple, linear-control-flow, straightforward, non-pessimized code, without unnecessary abstractions or patterns.
4. Amortize memory allocations with arenas.

We especially try to limit use of third-party libraries and frameworks in order to own our entire stack, and maintain visibility into every line of code that goes into the final product. Much of the slowness of modern software comes not from this slow algorithm or that inefficient data structure, but from all the invisible bloat hidden inside the mainstream default software stack.

We're not writing crazy inline assembly or SIMD intrinsics or discovering new algorithms or whatever. We do some optimization, like using file mappings and multithreading stuff where it makes sense, but mostly we are just writing straightforward code that performs the actual task of executing an IDE. Modern computers are just fast.

It's a throwback to an era when software was way faster, despite running on hardware much slower than a phone today.

Reach out at support@codeperfect95.com.