Senior Java Backend Developer (Spring Boot / Quarkus / API)

About CodeNinja CodeNinja is a next-generation technology consulting firm specialising in AI-powered transformation, enterprise software delivery, and Quality Engineering. Headquartered in the Gulf region and operating across the MENA, South Asia, and global markets, CodeNinja partners with Tier-1 banks, government entities, and large enterprises to design, build, and run mission-critical technology programs. With deep expertise in QA transformation, test automation, DevOps modernisation, and AI/ML engineering, CodeNinja's teams combine global delivery standards with in-market contextual knowledge — ensuring outcomes that are compliant, scalable, and commercially aligned with client objectives. For the Client's Test Management Enablement & Automation engagement, CodeNinja brings a dedicated 12-person specialist team spanning Test Management, Automation Engineering, AI/ML, and Performance Testing — all governed under a structured 20-week program delivery framework. About the Role We are looking for a highly skilled Senior Java Backend Developer with strong expertise in building scalable microservices and APIs. The ideal candidate will have hands-on experience with Spring Boot or Quarkus and API management using IBM API Connect (APIC). Experience in the Open Banking domain will be considered a strong advantage. Key Responsibilities Design, develop, and maintain scalable microservices using Spring Boot and/ Quarkus Build, publish, and manage APIs using IBM API Connect (APIC) Ensure high performance, security, and scalability of backend systems and APIs Collaborate with cross-functional teams including product, QA, and DevOps Troubleshoot, debug, and resolve production issues efficiently Follow best practices for clean code, testing, and system design Containerize applications using Docker and deploy on Kubernetes/OpenShift Implement authentication/authorization using OAuth2/JWT standards Write unit, integration, and contract tests Collaborate with DevOps on CI/CD pipelines Participate in code reviews, design discussions, Agile ceremonies Monitor, troubleshoot, and optimize microservices performance in production Requirements 5+ years of experience in Java backend development Strong hands-on experience with Spring Boot and Quarkus Solid understanding of microservices architecture Familiarity with API security and performance optimization Java 11+ specifically (not just "Java backend development") OpenShift alongside Kubernetes (currently only Docker/K8s is nice-to-have — should move to required) Proficiency with Git and CI/CD tools (Jenkins, GitLab CI) Working knowledge of SQL/NoSQL databases Nice to Have Experience in Open Banking or financial services domain Knowledge of OAuth2, JWT authentication Hands-on experience with Docker, Kubernetes, and cloud platforms (AWS, Azure, or GCP) Apache Kafka or other messaging/event-streaming platforms Observability tools — Prometheus, Grafana, ELK Why Join Us Opportunity to work on scalable, enterprise-level systems Collaborative and growth-focused environment Exposure to modern technologies and architecture Disclaimer This job description outlines the primary responsibilities and qualifications for the role at the time of posting. It is not exhaustive and may evolve in line with business needs and project requirements. CodeNinja reserves the right to modify role scope as the engagement progresses. All candidates will be subject to standard background verification. Onsite positions require compliance with the client's site access, security, and NDA policies. CodeNinja is an equal opportunity employer and welcomes applications from all qualified individuals regardless of background.