[sidkshatriya]

Even though your question is a bit pointed, I think it is worth understanding what software is built upon Chez and Racket. The answers would be instructional to everyone. Here is some stuff, that I _do_ know -- there is probably a lot more usage in the wild:

Racket is used extensively in education and research relating to Scheme and programming languages in general. Lots of work on gradual typing, programming language semantics comes out of the Racket community. Many colleges around the world use Racket. Scheme/Racket is very pared down language and lends itself to this kind of work -- the principles of whatever you are studying shine through quite easily in a way that it may not if you were using C, Rust, Python etc. in the problem domain.

As noted elsewhere in the comments, Idris 2, an important dependently typed language outputs to Chez/Racket Chez. Previously it output C code which was then compiled.

See: https://en.wikipedia.org/wiki/Racket_(programming_language)#...

In general, Chez is probably a great language to use as a "base". It lends itself to embedding and is performant. Lua and some Javascript implementations come to mind as comparables. In general, we might not know much about Chez being used a lot in the wild because it could be tucked deep into various proprietary company products.

[vincent-manis]

I do not know why Cisco hired Kent Dybvig, the prime designer/implementer of Chez Scheme, or why they chose to host its repo. I suspect that answering this question would reveal significant production programs written using Chez Scheme.