Last month, I spoke at the first-ever Elixir Wizards Conference. It was a lightning talk walking through a refactor I did before the 2020 US Presidential Election, titled "Dealing With a Monster Ecto Query."
I work for a news company, so the presidential election is a huge deal; we can't have downtime. I knew which query was our bottleneck, so I optimized it right before the election. This took advantage of a few Elixir features, like atoms, the pin operator, and concurrency primitives.
You can watch the talk below: