itch.io is a website for hosting indie games, its implementation is unique because it’s written entirely in Lua (MoonScript). It runs inside of an nginx distribution called OpenResty. It uses coroutines for all asynchronous operations like database queries and HTTP requests. Overview of coroutines Coroutines in practice What’s wrong with async callbacks? The coroutine approach How OpenResty works Conclusion I like Lua for many reasons1, it gets the design of many core components correct: Errors ...