Java Backend

Wissen Technology; Mumbai, Bengaluru; Hybrid; INR 1,200,000 - 1,800,000; Full time

Job summary

Wissen Technology in Mumbai seeks a Senior Java Backend Developer with 5+ years of hands-on backend experience to design, develop, and maintain scalable systems using Java, Spring Boot, and microservices.

You will build REST APIs, implement event-driven patterns with Kafka, apply DSA-based problem solving, and collaborate in an Agile team to deliver reliable software. Strong OO design, performance tuning, and testing with JUnit/Mockito are expected.

Qualifications

• 5+ years of hands-on Java backend experience.
• Strong knowledge of object-oriented programming, data structures, and algorithms.

Responsibilities

• Design, develop, test, and maintain scalable backend applications using Java and Spring Boot.
• Build and maintain RESTful APIs and microservices.
• Implement microservices architecture, including service-to-service communication and fault-tolerant design.
• Develop event-driven applications using Apache Kafka, including producers, consumers, topics, partitions, and consumer groups.
• Apply OOPS principles, SOLID principles, and design patterns to develop maintainable code.
• Demonstrate strong problem-solving skills using Data Structures and Algorithms (DSA).
• Work with relational and NoSQL databases and optimize SQL queries.
• Implement exception handling, logging, security, and performance optimization.
• Write unit and integration tests using JUnit and Mockito.
• Participate in code reviews, technical discussions, and Agile/Scrum ceremonies.
• Troubleshoot production issues and ensure application reliability and scalability.
• Collaborate with cross-functional teams to deliver high-quality software solutions.

Skills

Java

Spring Boot

Microservices

Apache Kafka

DSA

OOPS

Job description

Role & responsibilities

Job Description: Java Backend Developer 5+ Years of Experience

Experience: 5+ Years

Job Title: Senior Java Backend Developer

Skills Required: Java, Spring Boot, Microservices, Apache Kafka, DSA, OOPS

Job Summary

We are looking for an experienced Java Backend Developer with 5+ years of hands-on experience in designing, developing, and maintaining scalable, high-performance backend applications using Java, Spring Boot, and Microservices architecture. The ideal candidate should have strong knowledge of object-oriented programming, data structures and algorithms, REST APIs, and event-driven architecture using Apache Kafka.

Key Responsibilities

• Design, develop, test, and maintain scalable backend applications using Java and Spring Boot.
• Build and maintain RESTful APIs and microservices.
• Implement microservices architecture, including service-to-service communication and fault-tolerant design.
• Develop event-driven applications using Apache Kafka, including producers, consumers, topics, partitions, and consumer groups.
• Apply OOPS principles, SOLID principles, and design patterns to develop maintainable code.
• Demonstrate strong problem-solving skills using Data Structures and Algorithms (DSA).
• Work with relational and NoSQL databases and optimize SQL queries.
• Implement exception handling, logging, security, and performance optimization.
• Write unit and integration tests using JUnit and Mockito.
• Participate in code reviews, technical discussions, and Agile/Scrum ceremonies.
• Troubleshoot production issues and ensure application reliability and scalability.
• Collaborate with cross-functional teams to deliver high-quality software solutions.

Required Technical Skills

1. Core Java

• Strong knowledge of Java 8+ features, including Streams, Lambda Expressions, and Functional Interfaces.
• Collections Framework, Multithreading, Concurrency, Exception Handling, and JVM fundamentals.
• OOPS concepts: Encapsulation, Inheritance, Polymorphism, and Abstraction.
• SOLID principles and commonly used design patterns.

2. Spring Boot and Spring Framework

• Hands-on experience with Spring Boot and dependency injection.
• Spring MVC, Spring Data JPA, Hibernate, and REST API development.
• Spring Security and authentication/authorization fundamentals.
• Configuration management, validation, and exception handling.

3. Microservices Architecture

• Design and development of independent, scalable microservices.
• Inter-service communication using REST APIs and messaging.
• Service discovery, API Gateway, load balancing, and centralized configuration.
• Resilience patterns such as circuit breakers, retries, and timeouts.
• Distributed logging, monitoring, and tracing.

4. Apache Kafka

• Understanding of Kafka architecture and event-driven systems.
• Experience developing Kafka producers and consumers.
• Knowledge of topics, partitions, offsets, consumer groups, and message ordering.
• Error handling, retries, dead-letter topics, and message processing reliability.
• Understanding of delivery semantics and idempotent processing.

5. Data Structures and Algorithms (DSA)

• Strong understanding of arrays, strings, linked lists, stacks, queues, trees, graphs, and hash maps.
• Searching, sorting, recursion, and common algorithmic techniques.
• Time and space complexity analysis using Big O notation.
• Ability to solve coding problems efficiently.