My name is Claudio De Sio Cesari, I am an Oracle trainer, book author and senior software architect. Since 1999 I’ve started working as a freelance IT consultant for several universities, ministerial authorities and IT companies, especially for Sun Microsystems. I am the author of the "Manuale di Java" book series from version 6 to 9, Italian bestsellers, all published by Hoepli. My latest book on Java 15 was published in September 2020 in Italy and is called “Il nuovo Java”. Recently, I’ve also published with Amazon my first (2 volumes) book in English (see www.javaforaliens.com).