>The large "rewrite in language X" projects, [...] significant cost of time, effort and users.
Well... if you're pre-qualifying the hypothetical rewrite with "large", that already means we take as a given it will require significant time & effort. (Unless there's a sufficiently smart automatic transpiler tool like a future ChatGPT-v17.)
There have been some successful big rewrites. Google rewrote the web crawlers from Java to C++. They also rewrote the search results front page from Java to C++. Microsoft rewrote C# compiler from C++ to C#. Go rewrote the compiler from C to Go.
In any case, for curiosity... I ran the CLOC tool to count lines-of-code in the main NGINX repo ./src/* subdir. A project to convert ~165k of C to Rust is small enough to be doable by a small team. "Small" being 1 or 2 developers. (I'm not recommending they rewrite in Rust but just comparing the scope of the work to the resources.)
Semi-related footnote is Cloudflare replaced NGINX with in-house Pingora and that was written in Rust: https://hn.algolia.com/?q=pingora
Well... if you're pre-qualifying the hypothetical rewrite with "large", that already means we take as a given it will require significant time & effort. (Unless there's a sufficiently smart automatic transpiler tool like a future ChatGPT-v17.)
There have been some successful big rewrites. Google rewrote the web crawlers from Java to C++. They also rewrote the search results front page from Java to C++. Microsoft rewrote C# compiler from C++ to C#. Go rewrote the compiler from C to Go.
In any case, for curiosity... I ran the CLOC tool to count lines-of-code in the main NGINX repo ./src/* subdir. A project to convert ~165k of C to Rust is small enough to be doable by a small team. "Small" being 1 or 2 developers. (I'm not recommending they rewrite in Rust but just comparing the scope of the work to the resources.)
Semi-related footnote is Cloudflare replaced NGINX with in-house Pingora and that was written in Rust: https://hn.algolia.com/?q=pingora