Back-End Engineer (Java, Payments)

Quick Facts

• Role: Back-End Engineer (Java, Payments)
• Industry: Financial services and payments

Description

Build scalable, secure back-end services for business-critical payment solutions. Collaborate with an Agile team to design, develop, and enhance modern back-end applications using Java and Spring Boot, integrated with PostgreSQL and AWS.

Responsibilities

• Design, develop, and deliver scalable, secure back-end services using Java 25 and Spring Boot 4
• Develop and maintain RESTful APIs, microservices, and integrations with PostgreSQL and AWS
• Write clean, maintainable, testable code; contribute to technical reviews and engineering standards
• Analyse and resolve technical challenges; optimise application and database performance
• Contribute to improving system reliability, security, and scalability

Requirements

• 5–10 years of hands-on Java and Spring Boot experience, including Java 25 and Spring Boot 4
• Strong understanding of object-oriented programming, microservices architecture, and RESTful APIs
• Practical experience with PostgreSQL, including database design, SQL query optimisation, and efficient data management
• Hands-on experience with AWS cloud services and developing/integrating cloud-based applications
• Ability to deliver technical solutions independently while collaborating in Agile/Scrum

Bonus Points

• Experience delivering solutions in financial services, payments, or transaction-processing environments
• Familiarity with AWS services: ECS, EKS, Lambda, RDS, S3, CloudWatch
• Containerisation technologies: Docker, Kubernetes; CI/CD pipelines and automated deployment
• Automated testing: JUnit, Mockito, integration testing tools
• Event-driven architecture, messaging (e.g., Kafka), and monitoring/observability practices

Benefits

Hybrid cooperation with the option to provide services from the Warsaw office, depending on project needs.