Explore higher-order functions and the proposed `function_ref` abstraction in C++20 through this comprehensive conference talk. Dive into practical examples of how higher-order functions can enhance code quality and developer productivity in production environments. Learn about the implementation and specification of `function_ref`, a lightweight wrapper for callable objects that facilitates compiler optimization and inlining. Discover use cases for higher-order functions, including parallel algorithms, synchronicity, AI guards, and benchmarking. Compare `function_ref` to other techniques for implementing higher-order functions, and understand its potential future extensions. Gain insights into template parameters, polymorphism, and construction related to `function_ref`. Presented by Vittorio Romeo, an experienced Software Engineer at Bloomberg L.P., this talk offers valuable knowledge for C++ developers looking to leverage functional programming patterns in their work.