Books

Development

• Effective Java, 3rd Edition
• Java Performance, 2nd Edition by Scott Oaks
• Core Java 11 Fundamentals, Second Edition by Cay S. Horstmann
• Core Java 11 Advanced, Second Edition by Cay S. Horstmann
• Clean Code by Uncle Bob
• Modern Java in Action
• Clean Architecture: A Craftsman's Guide to Software Structure and Design (Robert C. Martin Series) 1st Edition
• Refactoring: Improving the Design of Existing Code (2nd Edition) (Addison-Wesley Signature Series (Fowler)) 2nd Edition
• The Pragmatic Programmer: Your Journey To Mastery, 20th Anniversary Edition (2nd Edition) 2nd Edition
• The Art of Multiprocessor Programming 2nd Edition
• Java Concurrency in Practice
• Code Complete: A Practical Handbook of Software Construction, Second Edition 2nd Edition
• Head First Design Patterns
• Head First Object-Oriented Analysis and Design 

Testing

• Test Driven Development: By Example,  Kent Back
• The Art of Unit Testing, 2nd Edition , Roy Osherove
• Unit Testing by Vladimir Khorikov

Spring

•   Pro Spring 5: An In-Depth Guide to the Spring Framework and Its Tools 

Architecture 

• Microservices Patterns by Chris Richardson
• Building microservices by Sam Newman
• Production ready microservices by Susan Fowler
• Domain Driven Design by Eric Evans

DevOps

• Continuous Delivery by Jez Humble
• Release it! by Michael Nygard
• Continuous Delivery with Docker and Jenkins by Rafał Leszko

Courses :

• Top 5 Multithreading courses : link