This chapter should leave you prepared for the defect type displacement taking place in the functional-first development in comparison to other development paradigms. A decreased rate of run-time errors typical to F# code shortens the time to market for developed systems and releases development resources for performance optimizations if they are deemed necessary.

We have reached the end of the book, where I equipped you with a whole slew of patterns of idiomatic F# use. The key assumption that the book makes is that such use requires from developers that come from other programming paradigms a certain shift in thinking habits, a distinct angle of seeing problems, and correspondent patterns and techniques populating the functional programmer tool belt. At this point you should be able to approach thinking through any problem by decomposing it into a handful of known building blocks and then composing the solution with appropriate functions and combinators. You also were shown the benefits of using standard F# algebraic data types over crafting custom .NET classes. Rely on patterns that you have acquired here in your functional designs; retain, recall, and reuse them in your day-to-day practices.

I hope that this book may guide you onto a path to the field of idiomatic functional programming. Good luck getting there!