Senior Software Engineer (Payments)

Responsibilities

State-of-the-art Java development in a payments domain! Microservices in AWS with a DevOps culture, cross-functional Scrum teams, and full ownership of systems powering critical transactional flows.

We are looking for a Senior Software Engineer with strong experience in payment systems who will design and scale services handling high-volume, business-critical payment processes.

• Design and implement highly available and scalable backend components for payment services, including payment flows such as authorization, capture, and refunds.

• Build and evolve payment integrations with external providers (e.g. Adyen, Stripe, PayPal) and internal payment orchestration layers.

• Take end-to-end ownership of services, including architecture, development, QA, security, and operations in a DevOps setup.

• Contribute to event-driven, distributed systems using Java, Spring Boot, Kafka, and AWS.

• Collaborate closely with Product Owners and stakeholders to shape payment-related features and improvements.

• Ensure reliability, performance and security of payment systems through monitoring, alerting and continuous improvement.

• Work in a cross-functional Scrum team, contributing through code reviews, pair programmin and knowledge sharing.

Benefits

• Motivizer Benefits Platform to choose and manage all your benefits in one place. You receive a budget (550 PLN monthly). You can choose medical care package, meal tickets, sports cards (we have Multisport and on preferential terms, we have membership cards to one of the most popular Gyms), cinema tickets, shop vouchers, discounts and many more.

• Language Courses – you'll have access to a multi-language learning platform enabling you to practice you language skills and learn new ones!

• Regular and systematic further training opportunities - both internally and from external providers. We support your ongoing learning and development.

• Cooperation within an internal community is our everyday reality. We have networking events, coding challenges, and company parties for different occasions.

Qualifications

• Completed university degree in Computer Science, Data Science, Mathematics, or a comparable technical field.

• 5+ years of experience in backend development of scalable, distributed systems using Java and Spring Boot.

• Proven hands-on experience in the payment domain is required, including building or integrating payment gateways, payment orchestration or transactional systems.

• Strong understanding of payment processes such as authorization, capture, settlement and refunds.

• Experience integrating payment providers such as Adyen, Stripe, PayPal or similar platforms.

• Practical experience with AWS, Kafka, Docker, Terraform, and SQL-based databases (e.g. PostgreSQL).

• Strong quality mindset, including testing, performance optimization, and secure coding practices.

• Fluent communication skills in English and Polish, with openness to hybrid work in Katowice.

About OBI Smart Technologies

WHO ARE WE: We are a joint venture between OBI and Reply Group, responsible for co-designing, building and operating mission-critical digital platforms for commerce, customer service, and omnichannel retail.

OUR MISSION: "We unite technology leadership with deep retail vision to implement standardized processes and scalable digital products that drive efficient support for one of Europe’s largest DIY retailers. Leveraging proven best practices, we advance the internationalization of products and the digital mindset of our partners, delivering consistent and business-critical solutions to support the targets of our customer."