Software Engineer - Work from Office - 2nd Round F2F interview mandatory

Job Description: Java Backend Developer Role Title: Java Backend Developer Target Experience: 3.0 4.0 Years of Experience (YOE) PDF   Target Budget: 10 LPA PDF   Domain Focus: Secure Backend Architecture, Payment / Fintech Integration, Microservices, and High-Performance API Engineering PDF + 3   Position Overview We are looking for a Java Backend Developer with 34 years of experience to join our backend engineering team . The ideal candidate will design, build, and optimize scalable, secure backend systems, transaction workflows, and RESTful APIs . You will be responsible for handling production databases, implementing secure authorization mechanisms, processing high-concurrency microservice workloads, and identifying performance bottlenecks . PDF + 4   Key Responsibilities & Core Competencies 1. Microservices & Core Backend Architecture Design, build, and deploy production-ready RESTful APIs using Java 8/17+ and Spring Boot .   Implement scalable microservice interactions utilizing synchronous REST/Feign Clients and asynchronous messaging via Apache Kafka .   Develop clean, maintainable backend code adhering to SOLID principles, design patterns (Singleton, Factory, Builder, Strategy), and Spring AOP for cross-cutting concerns (logging, exception handling) .   Technical Study Focus Areas: Java Core & Modern Features: Master Streams API, Functional Interfaces, Lambda Expressions, Optional handling, and internal mechanics of Collections ( HashMap , ConcurrentHashMap ) .   Multithreading: Core concurrency controls, thread safety, synchronized vs. ReentrantLock , volatile variables, ExecutorService management, and race condition prevention .   Spring Framework: Deep dive into Spring Bean lifecycles, dependency injection mechanisms, auto-configuration ( @Component , @Service , @Repository ), and microservices patterns .   2. Database Engineering & Performance Tuning Write and maintain complex SQL queries (joins, aggregations, subqueries) across relational databases (PostgreSQL, MySQL, Oracle) .   Identify latency bottlenecks and optimize query execution using indexing strategies and database execution analysis ( EXPLAIN plans) . Manage data persistence through Spring Data JPA and Hibernate ORM while controlling transaction boundaries . Technical Study Focus Areas: SQL Optimization: Index creation techniques, composite indexes, query execution tree interpretation ( EXPLAIN ), and data structure indexing . ORM Performance: Transaction management via @Transactional , Hibernate caching levels, and resolving common performance pitfalls like the N+1 query problem . Caching & NoSQL: Fundamental data operations with NoSQL databases (MongoDB) and in-memory caching strategies utilizing Redis . 3. Security, Domain Protocols & Transaction Processing Secure enterprise APIs and microservices using Spring Security, JWT (JSON Web Tokens), and OAuth 2.0 protocols . Apply application security mechanisms, including AES/RSA encryption, OTP validations, and secure credential storage . S upport financial transaction workflows, API integrations (UPI, FASTag, BBPS, or IMPS/NEFT/RTGS payouts), or domain messaging standards such as ISO 8583 . Technical Study Focus Areas: Security Architecture: Implementation of JWT filter chains, role-based access control (RBAC), token validation, and OAuth2 authorization server flows . Data Protection: Symmetric and asymmetric cryptographic practices (AES vs. RSA) for sensitive data payloads . Domain Integration: Message parsing, validation rules, transactional consistency, and handling high-concurrency event-driven processing with Kafka .   4. Deployment, Monitoring & Production Troubleshooting Package applications using Docker containers and integrate with modern CI/CD deployment pipelines (Tekton, Jenkins) .   Provide L1/L2 production support, root-cause analysis (RCA), and continuous debugging using application logs . Monitor health status, performance metrics, and service availability using Grafana, Kibana, or Postman testing suites . Technical Study Focus Areas: Containerization: Crafting Dockerfiles, environment variables management, container network configurations, and deployment strategies . Observability: Analyzing application logs via Kibana/Grafana dashboards, stack trace analysis, and system health diagnosis .   Testing: Unit testing and test-driven development (TDD) principles using JUnit and Mockito frameworks .   Desired Qualifications Education: Bachelors Degree in Computer Science, Engineering, or related technical field (or equivalent CDAC certification) .   Primary Skillset: Core Java, Java 8/17+, Spring Boot, Microservices, REST APIs, SQL (PostgreSQL/MySQL), Spring Security, Docker, Git . Good to Have: Hands-on exposure to Angular/React front-end frameworks, Redis caching, AWS cloud infrastructure (EC2, EKS), or Spring Batch pipelines .