Read
Effective Java
A must, if you want to say you know Java.
Java Concurrency In Practice
The Thread Items in 'Effective Java' are very generic, this book can be consider the java concurrency manual
Head First Design Patterns
Clean Code
Good read about generic programming techniques by Uncle Bob
Design patterns : elements of reusable object-oriented software
JavaScript: The Definitive Guide
Excellent book, the only part I would recomment to check somewhere else is event bubbling and capturing, it is way better explained in the firefox developers page
JavaScript: The Good Parts
The C Programming Language (2nd Edition)
MongoDB: The Definitive Guide
Beginning Python: From Novice to Professional
Learn Objective-C on the Mac
Java 8 in Action: Lambdas, Streams, and functional-style programming
Programing in Scala
Consider also checking AKKA, as it replaces the original scala concurrency module
Learning Spark
A very hands-on book, It is a good and fast introduction to Spark. The Spark SQL chapter is outdated (SchemaRDD has been replaced by DataFrame) and can be skipped, the official documentation is excellent.
Learning Apache Kafka
Very similar to the official documentation.
Apache Kafka
Very similar to the official documentation.
Apache Flume. Distributed Log Collection For Hadoop (2nd Edition)
HBase The Definitive Guide (2nd Ed)
Learning Apache Cassandra
Big Data - Principles and best practices of scalable real-time data systems
Elasticsearch - The Definitive Guide
Hadoop: The Definitive Guide
Reading
Fast Data Processing with Spark 2
Kafka: The Definitive Guide
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