it is https://devguard.io/ which is being rewritten from rust to ZZ in this branch https://github.com/devguardio/carrier/tree/zz

Very interesting.

Can you tell us a little more about the reasons of the rewrite from rust?

I'm not involved, but one obvious answer is: broader portability than Rust (this is explicitly called out in the ZZ article). Clearly devguard is targetting a broader set of devices than the limited set Rust currently targets (x86; arm, mips, riscv in tier 2, with various caveats for bare metal targets).

Thanks!