I chose Golang as a language to write Tango because it's super easy to get started with. I also considered Rust, but learning curve of it is much higher than in Golang. I felt like I would need to spend an endless amount of time to even get the hello world app working in Rust. While easy to learn, Golang still shows good performance, multithreading out of the box and fun to implement.
I also could choose PHP and create a phar-based tool, but I was not sure that it would be a good choice as I want to scale to be able to process Gbs of access log data