One of the exciting announcements this year was Lumen, an alternative BEAM implementation designed for WebAssembly. But what actually is WebAssembly and why has it received so much news lately? It is afterall, a recommendation (besides HTML, CSS and JS) by the WWW Consortium and 4th language to run natively in the browser. In this talk, we'll zoom into the details and demystify some of it's magic by building a WASM interpreter in Elixir.