A strong backend developer should possess a robust understanding of server-side technologies, database management, API development, and deployment practices.

Core Programming Languages and Frameworks :

- Java (Version 11 and above) : Proficiency in Java is fundamental. The candidate should be comfortable with object-oriented programming concepts, multi-threading, collections, exception handling, and newer features like Streams API, var keyword, functional interfaces, and lambda expressions introduced in Java 8 and beyond.

- Spring Boot (Version 2.7+) : In-depth knowledge of Spring Boot for building RESTful microservices. This includes understanding core modules such as Spring Web, Spring Data JPA, Spring Security, Spring Actuator, and Spring Validation. Ability to create loosely coupled, testable services using Dependency Injection and Annotations.

Database Technologies :

- Oracle DB Fundamentals : Good grasp of relational database principles, indexing, query optimization, and data modeling. Familiarity with PL/SQL for writing stored procedures and triggers.

- JDBC, Hibernate, HQL, and SQL : Proficiency in connecting Java applications to databases using JDBC. Experience with Hibernate ORM framework for object-relational mapping, HQL for querying objects, and writing complex SQL queries for data manipulation.

Data Formats and Web Technologies

- Data Formats : Understanding and experience in handling data formats like JSON, XML, and YAML for configuration and data interchange.

- RESTful Web Services : Ability to design and consume REST APIs using Spring Boot, with a strong grasp of HTTP methods, status codes, and best practices in designing stateless services. Working knowledge of API testing and documentation.

Version Control and Collaboration Tools :

- Git & Bitbucket : Experience with distributed version control systems like Git. Ability to manage branches, resolve merge conflicts, and follow branching strategies.

- Tools : Comfortable with Git Bash for command-line operations and SourceTree for a graphical Git interface.

- JIRA & Confluence : Familiarity with Agile tools for task tracking (JIRA) and documentation (Confluence). Experience participating in sprint planning, daily stand-ups, and retrospectives.

CI/CD and Build Tools :

- CI/CD : Exposure to continuous integration and deployment pipelines using Jenkins or similar tools. Ability to automate builds, tests, and deployments to various environments.

- Build Tools : Experience with Maven and Gradle for dependency management and project configuration.

- Application Servers : Deployment and management of applications on Apache Tomcat. Testing and IDEs

Postman : Proficient in testing REST APIs, managing collections, and using environment variables for different testing stages.

- IDEs : Comfortable working with Eclipse IDE and IntelliJ IDEA, with proficiency in debugging, code navigation, and plugin integration.

Optional but Valuable Skills :

- Messaging Protocols : Familiarity with asynchronous messaging protocols such as AMQP 0-9-1 and AMQP 1.0.

- Message Brokers : Experience with enterprise messaging systems such as RabbitMQ, Apache ActiveMQ, and Azure Service Bus for decoupled communication.

- Integration Patterns : Understanding of messaging patterns like Publisher/Subscriber and Point-to-Point.

- Event-Driven Architecture : Knowledge of designing systems based on message queuing, event sourcing, and asynchronous processing.