Learning paths

Job-ready backend developer

Everything between "I know Java" and "I can build a production Spring Boot service": tools, testing, databases, Spring and deployment.

  • For: You know the Java basics and want to build and ship REST APIs.
  • By the end: You can build, test, secure and deploy a Spring Boot REST API backed by PostgreSQL.
  • Size: 33 lessons (1 h 41 min of reading, plus time to try the code), intermediate
Start with equals(), hashCode() and the Object contract
  1. Exception handlingCore APIs, intermediate, 5 min
  2. Collections framework: choosing the right oneCore APIs, intermediate, 3 min
  3. How HashMap works insideCore APIs, advanced, 3 min
  4. Generics and wildcardsCore APIs, intermediate, 3 min
  5. Lambdas and functional interfacesModern Java, intermediate, 3 min
  6. Stream APIModern Java, intermediate, 3 min
  7. Optional: handling absenceModern Java, intermediate, 3 min
  8. Build tools: Maven and GradleTools and testing, beginner, 3 min
  9. Logging with SLF4J and LogbackTools and testing, intermediate, 3 min
  10. Unit testing with JUnit 5Tools and testing, intermediate, 3 min
  11. Mocking with MockitoTools and testing, intermediate, 3 min
  12. JSON with JacksonTools and testing, intermediate, 3 min
  13. Annotations and reflectionTools and testing, advanced, 3 min
  14. JDBC: talking to databasesJDBC, JPA and Hibernate, intermediate, 3 min
  15. JPA vs Hibernate: what's the difference?JDBC, JPA and Hibernate, intermediate, 3 min
  16. Entity mapping and relationshipsJDBC, JPA and Hibernate, intermediate, 3 min
  17. Persistence context and entity statesJDBC, JPA and Hibernate, advanced, 3 min
  18. The N+1 problem (and how to fix it)JDBC, JPA and Hibernate, advanced, 3 min
  19. Transactions, propagation and lockingJDBC, JPA and Hibernate, advanced, 3 min
  20. Networking: sockets, TCP and URLsCore APIs, intermediate, 3 min
  21. IoC and dependency injectionSpring Core and Spring MVC, intermediate, 3 min
  22. Bean scopes and lifecycleSpring Core and Spring MVC, intermediate, 3 min
  23. Spring MVC request flowSpring Core and Spring MVC, intermediate, 3 min
  24. Auto-configuration and startersSpring Boot, beginner, 3 min
  25. Configuration, profiles and propertiesSpring Boot, intermediate, 3 min
  26. Spring Data JPA repositoriesSpring Boot, intermediate, 3 min
  27. REST APIs, validation and error handlingSpring Boot, intermediate, 3 min
  28. Spring Security and JWTSpring Boot, advanced, 3 min
  29. Testing Spring Boot appsSpring Boot, intermediate, 3 min
  30. Caching with Spring and RedisSpring Boot, intermediate, 3 min
  31. Docker, Kubernetes and observabilityMicroservices, intermediate, 3 min
  32. CI/CD with GitHub ActionsMicroservices, intermediate, 3 min

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