Senior Java Software Engineer

Trustfinity Services And Solutions; Bengaluru; On-site; INR 900,000 - 1,700,000; Full time

Job summary

Trustfinity Services And Solutions is seeking a backend engineer to design and implement scalable microservices using Java and Spring Boot. You will build RESTful APIs, manage data with PostgreSQL and MongoDB, and contribute to system design and reliability.

Join a collaborative team working across product, DevOps, and QA to ship high‑quality features. Strong knowledge of Kafka, multithreading, testing with JUnit/Mockito, and API documentation will help you excel.

Qualifications

• Proficient in Java 11/17, OO design, collections, streams, exception handling, JVM basics.
• Experience building microservices with Spring Boot, Spring Data JPA, validation, actuator, config management.
• Knowledge of JWT/OAuth2 and API security patterns.
• Solid understanding of microservices, inter-service communication, and distributed systems.
• Ability to design scalable backend systems with caching, resiliency and fault tolerance.
• Hands‑on with Kafka-based asynchronous event-driven architectures, DLQ, retries, idempotency, partitioning.
• Strong relational DB skills with PostgreSQL (design, indexing, transactions, query planning).
• Experience with MongoDB document modeling and aggregations.
• Knowledge of Java concurrency, thread pools, locks, CompletableFuture, and high-throughput patterns.
• Experience designing REST APIs with pagination, filtering, versioning, idempotency, and OpenAPI documentation.
• Experience writing unit and integration tests with JUnit, Mockito, Spring Boot Test, MockMvc

Responsibilities

• Design, develop, and maintain scalable microservices using Java and Spring Boot.
• Build and expose RESTful APIs with clean contracts, error handling, and documentation.
• Model data across PostgreSQL and MongoDB with efficient querying.
• Implement event-driven patterns using Apache Kafka for async communication.
• Write production-grade code with strong multithreading and concurrency management.
• Develop unit and integration tests using JUnit, Mockito, and Spring Boot Test.
• Contribute to code reviews and engineering best practices.
• Identify and resolve performance bottlenecks across services, databases, and pipelines.
• Collaborate with product, DevOps, and QA to ship features reliably.

Skills

Java

Spring Boot

Spring Security

Microservices Architecture

System Design

Apache Kafka

PostgreSQL

MongoDB

Multithreading & Concurrency

APIs

Unit Testing

Tools

Docker

Kubernetes

OpenAPI/Swagger

JUnit

Mockito

MockMvc

Jenkins

GitHub Actions

Job description

Key Responsibilities

• Design, develop, and maintain scalable microservices using Java and Spring Boot.
• Build and expose RESTful APIs with clean contracts, proper error handling, and thorough documentation.
• Design and manage data models across PostgreSQL and MongoDB, ensuring efficient querying and schema integrity.
• Implement and manage event-driven workflows using Apache Kafka for reliable, asynchronous communication between services.
• Write production-grade code with strong multithreading and concurrency management thread pools, locks, async patterns.
• Develop comprehensive unit and integration tests using JUnit, Mockito, or equivalent frameworks.
• Participate in code reviews and contribute to engineering best practices and architecture decisions.
• Identify and resolve performance bottlenecks across services, databases, and message pipelines.
• Collaborate with cross-functional teams including product, DevOps, and QA to ship quality features reliably.

MANDATORY SKILLS
Technical

• Java (4+ years): Strong hands‑on experience with Java 11/17, object‑oriented design, collections, streams, exception handling, JVM fundamentals, design patterns, and writing maintainable production‑grade code.
• Spring Boot: Strong experience building production‑grade microservices using Spring Boot, Spring Data JPA, Spring Validation, Spring Actuator, and configuration management.
• Spring Security: Awareness of JWT‑based authentication, OAuth2 flows, and API security patterns.
• Microservices Architecture: Solid understanding of service decomposition, inter‑service communication, and distributed system patterns.
• System Design: Ability to design scalable backend systems with considerations for resiliency, scalability, caching, and fault tolerance.
• Apache Kafka: Experience designing asynchronous event‑driven architectures using Kafka, including retries, dead‑letter queues (DLQ), idempotency, consumer scaling, partitioning, and message ordering.
• PostgreSQL: Strong understanding of relational database design, normalization, indexing, transactions, query optimization, and execution plans.
• MongoDB: Practical experience with document modeling, aggregations, and NoSQL data access patterns.
• Multithreading & Concurrency: Strong understanding of Java concurrency, thread pools, synchronization, locks, CompletableFuture, concurrent collections, and performance implications in high‑throughput applications.
• APIs: REST API design, pagination, filtering, versioning, idempotency, authentication, rate limiting, and API documentation using OpenAPI/Swagger.
• Unit Testing: Experience writing unit, integration, and API tests using JUnit, Mockito, Spring Boot Test, and MockMvc.

GOOD-TO-HAVE SKILLS
These will set you apart

• "BPM & Workflow Engines: Hands‑on experience with any BPMN‑based workflow engine (e.g., Camunda, Flowable, or equivalent) designing workflows, integrating service tasks, and managing process instances.
• Docker & Kubernetes: Familiarity with containerizing services and deploying to orchestrated environments.
• CI/CD Pipelines: Experience with Jenkins, GitHub Actions, or similar tools for automated build and deployment.
• AI/ML Integration: Experience integrating external AI/LLM services (OpenAI, Anthropic, Gemini, Azure OpenAI, etc.) into backend applications through REST APIs or SDKs.
• Cloud Platforms: Basic familiarity with AWS, GCP, or Azure for deployment, managed databases, or messaging services.

WHO YOU ARE

• Backend-focused, detail‑oriented you take pride in clean code, efficient data access, and reliable service design.
• Ownership-oriented: You take problems from ambiguity to solution independently.
• Startup-ready: You are comfortable with changing priorities, lean teams, and high‑impact work.
• A strong communicator who can align with cross‑functional teammates quickly.