Senior Java Developer

About the role

We are looking for a Senior Java Backend Engineer to design, develop and maintain the backend systems of our e‑commerce payment gateway (NGenius Online). The role works closely with frontend, product and DevOps teams to ensure a secure, scalable and high‑performance platform.

Key responsibilities

• Lead the design, development, and maintenance of backend systems for the e‑commerce payment gateway, ensuring high performance and scalability.
• Design efficient MongoDB and MySQL schemas, optimize queries, and maintain data integrity.
• Build and maintain Java microservices using Spring Framework, Spring Boot, Spring Cloud, and Quarkus.
• Deploy and scale services on cloud platforms (AWS, Azure) utilizing serverless computing, containers, Kubernetes, and Helm charts.
• Implement security best practices, encryption, and access controls; mitigate vulnerabilities and manage version migrations.
• Monitor and optimize backend performance, identify bottlenecks, and improve response times.
• Investigate and resolve backend issues in collaboration with DevOps and frontend teams.
• Participate in code reviews, mentor junior engineers, and uphold high code quality standards.
• Maintain thorough technical documentation for APIs and microservices.

Required profile

• Bachelor’s degree in Computer Science or equivalent.
• Minimum 6 years of relevant professional experience.
• Strong expertise with MongoDB and MySQL database systems.
• Extensive experience with Java frameworks such as Spring (Framework, Boot, Cloud) and Quarkus.
• Hands‑on experience with microservices architecture and design patterns.
• Knowledge of security standards and tools including Keycloak, OAuth2.0, and OpenID.
• Familiarity with cloud platforms (AWS, Azure) and containerization technologies (Docker, Kubernetes, Helm).
• Proficiency with HTTP, REST, SOAP, XML, WSDL, and API design.
• Experience with streaming platforms like Kafka or Azure Event Hubs is a plus.
• Ability to write unit tests using JUnit.
• Functional knowledge of the financial or banking domain is a plus.

Required skills

• Java
• Spring Framework
• Spring Boot
• Spring Cloud
• Quarkus
• MongoDB
• MySQL
• Microservices
• Keycloak
• OAuth2.0
• OpenID
• Kafka
• Azure Event Hubs
• AWS
• Azure
• Docker
• Kubernetes
• Helm
• HTTP
• REST
• SOAP
• XML
• WSDL
• JUnit
• Kibana
• Grafana