This reminds me of back in 2003, a friend of mine worked for an online casino vendor; basically, if you wanted to run an online casino, you'd buy the software from a company and customize it to fit your theme.
They were often written in Java, ASP.NET, and so on. They were extremely heavyweight. They'd need 8-10 servers for 10k users. They hogged huge amounts of RAM.
My friend wrote the one this company was selling in C. Not even C++, mind you, just C. The game modules were chosen at compile time, so unwanted games didn't exist. The entire binary (as in, 100% of the code) compiled to just over 3 MB when stripped. He could handle 10k concurrent users on one single-core server.
I'm never gonna stop writing things in Python, but it still amazes me what can happen when you get down close to the metal.