Dealing with a Monster Ecto Query

Learn how to optimize complex Ecto queries in Elixir through a real-world case study from the Axios mobile app. Discover techniques for handling gnarly queries with multiple OR cases that were limiting system capacity before a high-traffic event. Explore how leveraging specific Elixir features enabled a 600% capacity increase just before the 2020 election, challenging the conventional wisdom of pushing all processing to the database. Gain insights into when and how to move query logic from the database to application code for better performance, using practical examples from a production system that needed to scale rapidly under pressure.