Raúl Estrada is a programmer since 1996 and Java Developer since 2001. He loves functional languages such as Scala, Elixir, Clojure, and Haskell. He also loves all the topics related to Computer Science. With more than 12 years of experience in High Availability and Enterprise Software, he has designed and implemented architectures since 2003.

His specialization is in systems integration and has participated in projects mainly related to the financial sector. He has been an enterprise architect for BEA Systems and Oracle Inc., but he also enjoys Mobile Programming and Game Development. He considers himself a programmer before an architect, engineer, or developer.

He is also a Crossfitter in San Francisco, Bay Area, now focused on Open Source projects related to Data Pipelining such as Apache Flink, Apache Kafka, and Apache Beam. Raul is a supporter of free software, and enjoys to experiment with new technologies, frameworks, languages, and methods.

I want to thank my family, especially my mom for her patience and dedication.

I would like to thank Master Gerardo Borbolla and his family for the support and feedback they provided on this book writing.

I want to say thanks to the acquisition editor, Divya Poojari, who believed in this project since the beginning.

I also thank my editors Deepti Thore and Amrita Noronha. Without their effort and patience, it would not have been possible to write this book.

And finally, I want to thank all the heroes who contribute (often anonymously and without profit) with the Open Source projects specifically: Spark, Mesos, Akka,  Cassandra, and Kafka; an honorable mention for those who build the connectors of these technologies.