Senior Backend JVM Engineer (Fintech)

TL;DR

Senior Backend JVM Engineer (Fintech): Integrating new payment service providers into an existing platform with an accent on adapter-based microservice architecture and payment lifecycle management. Focus on implementing payment flows using Java/Kotlin and Spring Boot/Cloud, ensuring scalability and consistency within a high-stakes enterprise project.

Location: Remote

Salary: 1,400–1,750 PLN net+VAT/day

Company

An international software service provider specializing in building expert teams for complex enterprise projects.

What you will do

• Implement payment service provider integrations using Java or Kotlin in an adapter-based architecture.
• Develop and validate end-to-end payment flows including tokenization, execution, refunds, and chargebacks.
• Operate within a Spring Boot and Spring Cloud microservices environment to ensure scalable and testable code.
• Maintain technical specifications and documentation using GitHub Spec-Kit.
• Collaborate within a focused micro-team to meet enterprise customer requirements by August 2026.
• Participate in daily remote check-ins and agile scrum ceremonies.

Requirements

• 4+ years of backend development experience with Java and Kotlin.
• Extensive knowledge of Spring Boot and Spring Cloud in distributed systems.
• Solid FinTech background with hands-on experience in payment lifecycles and PSP integrations.
• Proficiency in PostgreSQL and asynchronous messaging with RabbitMQ.
• Experience with containerized environments, specifically AWS EKS.
• English language proficiency (B2-C1 required).

Nice to have

• Experience with UK BACS Direct Debit or Instant Bank Pay.
• Familiarity with GoCardless Success+ platform.
• Hands-on experience with GitHub Spec-Kit.

Culture & Benefits

• Remote work environment.
• B2B contract structure with defined daily rates.
• Private medical healthcare coverage.
• 50% subsidy on Multisport card.
• Collaborative team culture focused on shared learning and continuous improvement.