This book wraps up a chain of events stretching along a period of almost two dozen years of my life. Behind all these events of various kinds and scopes were people whose valuable contributions and positive attitude allowed me to deliver. I want to use this opportunity and express my admiration for them.

Thanks to my Mom and Dad, who spotted my interest in math and computers early and provided a tremendous amount of love, understanding, and support needed for converting a kid’s passion into a profession.

I am grateful to my closest friends, who caught me at the brink of an academic career failure and helped me make a fresh start as a computer software practitioner. Michael and Michael, I value your help and our friendship tremendously.

I am so thankful to my first U.S. employer for being there for me, for his empathy, generosity, and friendliness. Bill, you personify for me the best of the genuine American spirit. I’ll never forget your helping hand.

Turning to the book’s subject, I must admit that my fascination with F# was influenced to a great extent by the alliance with the amazing F# community. Folks, I admire your professional excellence, knowledge-sharing generosity, your brilliant OSS contributions, your vibrant attitude. You are the source of permanent inspiration.

Further, this book never would have happened without continuing support from Jet.com, the e-commerce company that I have the privilege to work for. I praise you, Purple People, for the engineering courage of putting F# at the cornerstone of Jet’s technology, for the outstanding atmosphere of enthusiasm and thirst for knowledge, for the freedom to explore, for providing the necessary resources. Jet.com Technology is an exceptional workplace for software engineers to thrive. I hope that this book encourages more great folks to join us.

And finally, completing this book would never be possible without the support, sacrifice, patience and forgiveness that my family is continuously delivering my way. Thank you for everything, my dear, you are the best.