First and foremost, I would like to thank the amazing and continuously growing Scala community, the source of continuous enthusiasm. It's a fun and proud feeling to contribute to such a community. Then, to the team, Sandeep Mishra, Rohit Kumar Singh, Vaidehi Sawant, and Pavan Ramchandani—you guys get all the credit for the work done. Special thanks to our reviewer, Vasilis Nicolaou. His comments were helpful. I hope our book will be fun and informative to read.