Move on to JUnit 5
Baeldung
Engineering Principles in Everyday Life for Non-Engineers
Saeed Benjamin Niku
MongoDB: The Definitive Guide
Eoin Brazil & Kristina Chodorow & Shannon Bradshaw
Impractical Python Projects: Playful Programming Activities ...
Lee Vaughan
Hands-on Design Patterns and Best Practices with Julia
Tom Kwong
Kotlin Design Patterns and Best Practices
Alexey Soshin
Head First Design Patterns
Eric Freeman & Elisabeth Robson & Bert Bates
head first (1)
Domain-Driven Design - Tackling Complexity in the Heart of Software
Eric Evans
Implementing Domain-Driven Design
Vaughn Vernon