Binary protocols are all around us, HTTP/2, HPACK, or DNS are only a few examples. Pretty efficient on the transport layer they reduce size dramatically and enable a set of great features. But they are often more complex to implement and reason about. In this talk you will learn how you could implement a given binary protocol with Elixir. We will take a look at binary pattern matching, de- and encoding of strings and integers, binary data frames and extracting tests from RFC specs. And, we will take a look at how to implement the HPACK protocol as part of the HTTP/2 protocol so you will learn some of that along the way as well.