Java Back End Developer

Mergen Corporates; Hyderabad, Pune District, Bengaluru; On-site; INR 1,200,000 - 2,000,000; Full time

Job summary

Mergen Corporates is seeking a Java backend developer to design and implement scalable microservices in a Spring environment. You will build RESTful services, optimize data access, and collaborate with product teams across the lifecycle.

You will work with PostgreSQL, MongoDB, AWS, Docker, Kubernetes and CI/CD pipelines to deliver high-quality software. Prior experience in back-end stack technologies and mentoring is preferred.

Qualifications

• Strong experience with Java and Spring ecosystem, including Spring Boot, MVC, and security.
• Deep REST API design/implementation, with OpenAPI specs and API security controls.
• Relational and NoSQL databases, writes optimized SQL, ORM usage and data access patterns.
• Microservices architecture, DDD, design patterns and scalable data models.
• Proficient with unit/integration testing tools and CI/CD pipelines.

Responsibilities

• Design, implement, and maintain backend services with Java/Spring framework.
• Develop robust REST APIs, database queries, and microservice boundaries.
• Mentor juniors, conduct code reviews, and ensure code quality and security standards.

Skills

Java

Spring Boot

REST API

SQL

PostgreSQL

MongoDB

AWS

Kubernetes

Docker

CI/CD

OAuth2

JWT

OpenAPI

DDD

Unit testing

JUnit

Tools

Maven

Git

Postman

Swagger/OpenAPI

OpenTelemetry

Job description

Mandatory Technical Skills:

• Core Languages & Frameworks: Java (Spring Boot, Spring MVC, Spring

Data JPA, Spring Security) and Maven (Java 21, Spring Boot 4 environment

using Maven multi-module projects).

• API Design & Integration: Deep expertise in RESTful API engineering,

OpenAPI/Swagger specifications, Webhooks, API Security (OAuth2, JWT,

OIDC), gRPC and Netty.

• Databases & Persistence: Relational databases (PostgreSQL, Oracle,

MySQL) with strong SQL & ORM knowledge; exposure to NoSQL databases

(MongoDB, DynamoDB). Primarily using PostgresSQL.

• Architecture & Design: Microservices architecture, Object-Oriented Design,

Domain-Driven Design (DDD), design patterns, and data structure optimization.

• Testing & Quality: Unit testing (JUnit, Mockito, PyTest), automated integration

testing, and API testing (Postman, REST Assured).

• Migrations: Redis, Flyaway.
• Developer Efficiency & AI Tools: Comfortable leveraging AI-assisted coding

tools (e.g., Cursor, Gemini) to accelerate development, generate unit tests,

write documentation, and refactor code safely.

• Experience: Minimum 4-5 years of industry experience with 2+ years of

hands-on expertise in backend stack technologies.

Secondary & Infrastructure Skills:

• Secondary Languages & Frameworks: Python (FastAPI/Django).
• Authentication & Identity: OKTA, Keycloak, IAM.
• Cloud & DevOps: AWS / Google Cloud, Docker, Kubernetes, CI/CD pipelines

(GitLab CI / Jenkins).

• Messaging & Search: Kafka, RabbitMQ, Quartz Schedulers, Elasticsearch.
• Data Schemas & Tooling: JSON Schemas, Git version control, Unix/Linux

environment commands.

• Observability & Metrics: OpenTelemetry, Prometheus and Grafana.

Job Duties & Allocation

• [7080%] Backend Development: Design, code, and optimize high-throughput

REST APIs, database queries, batch schedulers, and server-side business

logic.

• [10–20%] System Architecture & Proof of Concepts: Participate in API

contract design, microservice boundary definition, database schema modeling,

and POC development.

• [10–20%] Quality, Mentoring & Collaboration: Perform code reviews, write

automated unit and integration tests, author API documentation, and mentor

junior developers.

Typical Work Day

• Collaborate with Product Owners, Architects, and Front-End UI developers to

define clean, versioned API contracts.

• Develop server-side applications and RESTful endpoints using Java/Spring

Boot or Python.

• Optimize SQL/NoSQL queries and database interactions for performance and

scale.

• Conduct peer code reviews and ensure compliance with coding and security

standards.

• Write automated unit and end-to-end integration tests.
• Participate in daily Agile standups, backlog refinement, and sprint planning in

  JIRA.

  • Deploy services to development/staging environments and support QA

  verification.