Emilien Kenler, after working on small web projects, began to focus on game development in 2008 when he was in high school. Until 2011, he worked for different groups and has specialized in system administration.

In 2011, Emilien founded a company to sell Minecraft servers while he was studying Computer Science Engineering. He created lightweight IaaS based on new technologies, such as Node.js and RabbitMQ. After that, he worked at TaDaweb as a system administrator, building its infrastructure and creating tools to manage deployments and monitoring. In 2014, he began a new adventure at Wizcorp, Tokyo. He graduated in 2014 from The University of Technology of Compiègne.

For Packt Publishing, Emilien has reviewed Learning Nagios 4, Wojciech Kocjan (http://www.packtpub.com/learning-nagios-4/book), and MariaDB High Performance, Pierre MAVRO (https://www.packtpub.com/big-data-and-business-intelligence/mariadb-high-performance).

Unnikrishnan Appukuttan Pillai is a Linux system administrator with experience in Linux and open source technologies. He has worked on the latest open source technologies in web hosting, virtualization, and cloud computing. In his 8 years of career, he has worked for leading companies such as Bobcares, IBM, Directi, and KnownHost.

Unnikrishnan has his website at http://www.mutexes.org/.

Alexei Yuzhakov has been working as a development manager of Parallels Plesk Panel. He lives in Novosibirsk, Russia. He likes to drink vodka with bears and code for fun. Software development is not only his job but also his favorite hobby.