Milica is web developer from Belgrade, currently writing for Google about performance optimizations and tools that can help you with that. Before that she was an intern at Mozilla where she worked on Servo engine and learned a lot about how browsers work. She's also a Mozilla Tech Speaker and a big believer in open web, always exploring new technologies that are moving it forward, like WebAssembly and WebXR.
WebAssembly is a new type of code that modern browsers can run and it's fast by design. You do not write WebAssembly, you compile other languages, like C++ or Rust, to WebAssembly. All major browsers support it and they are steadily working on adding new features.