The talk given by Frederico at the FOSDEM conference in 2023 focused on the concept of cognitive load in code bases and how it can be reduced. Frederico discussed various patterns and suggestions to improve code readability and understandability, such as using line of sight, choosing informative package names, handling errors properly, using pure functions, organizing code files based on newspaper-like structure, making use of synchronous functions, avoiding functions that lie about their behavior, and other tips. The talk emphasized the importance of reducing cognitive load for better code quality and maintainability.