Writing this book was hard work but also a great opportunity to try something new. Looking at more and more pages being created with time, I realized how rich ElasticSearch is and how difficult it is to fit the description of its features within the page limit. I hope that topics that finally made it to the book are the most important and interesting ones.

The biggest thank-you goes to all the people involved in the development of Lucene and ElasticSearch. Great work!

I would like to thank also the team working on this book. I am impressed how smoothly and quickly we passed through all the organizational stuff. Special thanks to the reviewers for a long list of comments and suggestions.

Last but not the least, thanks to all my friends, both those who persuaded me to write a book and those to whom it will be a complete surprise.