If I would choose another language it would be Rust. Why I did not choose Rust?

1. I speak fluently C++ and learning Rust would take me years. 2. Foodchain of libraries that I am intimately fimiliar with in C++ and I am not familiar with in Rust. Take Rust Tokyo, for example. This is the de facto the standard for how to build I/O backends. However if you benchmark Tokyo's min-redis with memtier_benchmark you will see it has much lower throughput than helio and much higher latency. (At least this is what I observed a year ago). Tokyo is a combination of myriad design decisions that authors of the framework had to do to serve the mainstream of use-cases. helio is opinionated. DF is opinionated. Shared-nothing architecture is not for everyone. But if you master it - it's invincible. (and yeah - there is zero chance I could write something like helio in Rust)...

Tokio is not a shared-nothing model - you’d be looking at Glommio [1] (from one of the contributors to Seastar) for that.

[1]: https://github.com/DataDog/glommio

The deal breaker for me was stable Rust doesn't have fast thread locals[1] nor stack probes for arm64[2].

[1]: https://github.com/rust-lang/rust/issues/29594

[2]: https://github.com/rust-lang/rust/issues/77071