Mackenzie Morgan

Senior Software Engineer at NextRoll

Mackenzie has been known to joke about being “really full stack,” from the browser all the way down to the Linux kernel. But now in the 2020s, her days as an Ubuntu Developer are long in the past, and (like so much of the industry) she’s hanging out around web servers. After being introduced to Elixir in 2020 to solve a major performance issue, Mackenzie discovered that functional programming works with her brain in a way object-oriented programming never did. (This came as a surprise! The first time someone tried to get her to try FP, it was a Haskell programmer saying scary words like “lambda calculus.”) When not writing code, Mackenzie studies and recreates 16th-century clothing, shoots archery, and gets chased by that darned green owl.

Typing with pixie dust

Legacy code. It can be…fragile. It really helps if you can already be sure what types your functions expect and return, but what if past-you didn’t include type specs, making life harder for now-you?

Thankfully, TypEr already exists, but what if we could sprinkle on some pixie dust and make it more automagic? There’s a Rebar3 plugin for that! Come learn about the tools used to create that plugin, discoveries along the way, and enhancements made to TypEr in the process.


Increase the likelihood people will start using type specs if they aren’t yet, and also demonstrate the ease of creating new rebar3 plugins using the rebar3 plugin framework.


Developers dealing with legacy code and rebar3