Java Developer

O projekcie: Location: Kraków, Poland (hybrid – 2 days/week from office) Contract type: B2B Rate: 140–150 PLN/h Project type: Long-term, enterprise, payments domain About the project For one of our global financial clients operating in the payments domain, we are building a new engineering team responsible for delivering a Future State Architecture for payment processing. The project focuses on creating a lean, reusable payment processing engine that will become the foundation of next-generation payment capabilities. The work is performed in an inner-sourcing model, with a strong emphasis on reuse, modernization, cloud adoption, and high engineering standards, enabling faster delivery of new product features at scale. Benefits - Private medical care (Medicover) - Sports card (Multisport or equivalent) - Life insurance - Long-term cooperation on a stable, enterprise-scale project - Access to modern technologies and large-scale distributed systems - Real influence on architecture and technical direction Opis Firmy Experis to światowy lider rekrutacji specjalistów i kadry zarządzającej w kluczowych obszarach IT. Z nami znajdziesz konkurencyjne oferty zatrudnienia oraz ciekawe projekty IT skierowane zarówno do ekspertów z wieloletnim doświadczeniem, jak i osób, które dopiero zaczynają swoją przygodę w branży IT. Oferujemy rekrutacje menedżerów i wysoko wykwalifikowanych konsultantów z doświadczeniem w branży IT. Experis jest częścią ManpowerGroup i został uznany za jedną z najbardziej etycznych firm na świecie. Wymagania: Required Qualifications & Experience - Bachelor’s degree in Computer Science, Engineering, or a related field  - 8+ years of experience as an API Engineer  - Strong experience in API design and architectural documentation (LLDs, gap analysis, data models)  - 5+ years of backend microservices development, application security, authentication, caching, and middleware  - 8+ years of Java experience (Go and/or Rust is a strong plus)  - Expertise in distributed systems, Spring Boot, microservices architecture  - Experience with Kafka, Docker, Kubernetes, service mesh  - Strong JVM tuning and performance optimization skills  - Experience with observability and monitoring tools (Grafana, Prometheus, Splunk, Jaeger, OpenTelemetry, etc.)  - Cloud & DevOps experience, including networking (VPC), IAM, sizing, and cost optimization  - Solid understanding of Linux, networking, storage, load balancing, and Kubernetes CNI  - SQL knowledge is a strong plus  - Experience in financial institutions or payment systems is highly desirable  - Excellent English communication skills  Nice to Have - Experience with Go or Rust  - Strong background in payments or large-scale financial systems  - Passion for mentoring, coaching, and technical leadership Codzienne zadania: - Deliver engineering expertise for future-state payment architecture and next-generation payment processing capabilities  - Design, build, and maintain highly available, resilient, and scalable backend services  - Produce high-quality, well-tested code and ensure all quality gates are exceeded  - Support the transformation and modernization of the existing payment landscape with strong cloud focus  - Actively participate in a wider delivery team contributing to new platform capabilities  - Resolve architectural and development blockers and provide hands-on technical guidance  - Collaborate closely with DevOps teams to enable CI/CD pipelines and DevSecOps practices  - Set engineering standards and lead by example within the team  - Act as a technical expert, identifying process improvements and preventing systemic issues  - Provide technical solutions to complex business and architectural problems  - Drive architectural decisions aligned with global standards and business strategy  - Maintain awareness of regulatory, security, and data privacy requirements  - Design, implement, review, and optimize systems for performance, resilience, and operational integrity  - Mentor and coach engineers, supporting their technical and professional growth