The past few years I've seen more projects use Go or Rust for heavy lifting alongside a higher-level language like PHP or JavaScript.

I've learned a little Go myself but don't know enough about Rust to understand when you'd choose one over the other. Vercel is currently migrating a codebase from Go to Rust, it's interesting to read the reasoning behind the decision.

For example:

Go's preference for simplicity at the filesystem was creating problems for us when it came to file permissions. Go lets users set a Unix-style file permission code: a short number that describes who can read, write, or execute a file.

While this sounds convenient, this abstraction does not work across platforms; Windows actually doesn't have the precise concept of file permissions. Go ends up allowing us to set a file permission code on Windows, even when doing so will have no effect.

In contrast, Rust's explicitness in this area not only made things simpler for us but also more correct. If you want to set a file permission code in Rust, you have to explicitly annotate the code as Unix-only. If you don't, the code won't even compile on Windows. This surfacing of complexity helps us understand what our code is doing before we ever ship our software to users.

Next to PHP, Go is a low-level language—but Rust is even lower. Looks like Go is great for heavy lifting on the web, but if you're into building tools to run in different environments Rust is where you want to be.