Expert Java API Engineer (Payment Processing)

Quick Facts

• Role: Expert Java API Engineer (Payment Processing)

• Focus: Future-state payment processing architecture and cloud-ready payment APIs

• Work model: Hybrid

• Location: Krakow-based opportunity

Description

As an Expert Java API Engineer, you will help deliver a future-state architecture for payment processing. You will build highly available, resilient, cloud-adoption-ready payment capabilities using modern microservice architectures—enabling new products to reach customers faster with greater quality and efficiency.

Responsibilities

• Deliver engineering expertise for future-state payment processing architecture

• Design, develop, test, debug, and document high-quality software and API solutions

• Build highly available and resilient payment processing services using modern microservice architectures

• Produce architectural artifacts, technical alternatives, data models, and low-level designs

• Partner with DevOps teams to enable automated infrastructure delivery, DevSecOps value streams, and CI/CD pipelines

• Provide technical leadership, architecture guidance, mentoring, and consultation to development teams

• Identify and resolve complex architectural, development, technical, and business issues

• Support modernization of the payment estate while ensuring compliance with relevant controls, standards, cybersecurity, and data privacy requirements

Requirements

• Bachelor’s degree in Computer Science, Engineering, or related field

• 15+ years of applied experience as an API Engineer and 10+ years of software engineering experience

• 10+ years of programming experience in Java

• Expert knowledge of distributed systems, microservices, and Spring Boot

• Strong expertise in Docker, Kubernetes, service mesh, Kafka, and Kubernetes CNI

• Experience with API design, application security, authentication, caching, middleware, and architectural documentation

• Expertise in JVM tuning, diagnostics, troubleshooting, and performance optimization

• Practical knowledge of cloud and DevOps technologies, including VPC/firewall, IAM, cloud sizing and costing, monitoring, and observability tools (Splunk, Grafana, Prometheus, Jaeger, Kiali, OpenTelemetry)

• Fluent English (written and verbal)

• Existing legal right to work in Europe

Benefits

• Work on next-generation financial services focused on resilience, modernization, and cloud adoption

• Technical leadership role across architecture, engineering delivery, and collaboration with DevOps/DevSecOps

• Build reusable payment capabilities to improve quality and efficiency