Java Developer (Backend)

Design, develop, test, and maintain backend services and RESTful APIs using Java and Spring Boot. • Build high-concurrency services using Java virtual threads on the Spring Boot servlet stack, with careful management of blocking I/O, database connection pools, and thread pinning. • Implement core financial features such as wallet accounts, transfers, merchant payments, and transaction ledgers with strict attention to consistency, atomicity, and auditability. • Design efficient PostgreSQL schemas, queries, and indexes; manage schema changes through versioned database migrations (Flyway). • Integrate with external systems including banks, card schemes, payment processors, and third-party identity/KYC services. • Apply secure coding practices and Spring Security standards for authentication, authorization, and protection of sensitive customer data. • Contribute to and reuse shared internal libraries to ensure consistency in logging, configuration, and security across services. • Write unit and integration tests; participate actively in code reviews and uphold team coding standards. • Act as third-line (L3) escalation for production incidents on a rotating on-call basis: diagnose root causes, deliver fixes, and contribute to post-incident reviews. • Package and deploy services in containerized environments (Docker, Kubernetes) on cloud infrastructure (AWS). • Work within an Agile/Scrum process: estimate tasks, manage tickets in Jira, and deliver to sprint commitments. • Produce and maintain clear technical documentation, API specifications, and Postman collections.

• Experience in fintech, banking, mobile wallets, or payment systems (e.g., card payment gateways, QR payments, double-entry ledgers). • Production experience with virtual threads, structured concurrency, and diagnosing pinning or connection-pool contention (e.g., HikariCP) under load. • Experience with database migration tools (Flyway or Liquibase) and PostgreSQL table partitioning. • Hands-on exposure to AWS services such as S3, IAM/STS, and managed identity or KYC services. • Experience with Kubernetes and CI/CD pipelines. • Awareness of GraalVM native images, JVM performance tuning, and observability tooling. • Understanding of information security and compliance frameworks relevant to financial services (e.g., PCI DSS, ISO/IEC 27001)