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January 3, 2026

Backend Product Engineer (Payments / Kotlin)

Senior • Remote

$150 - $180/

Łódź, Poland

As a Backend Product Engineer, you will work on one of the most critical parts of our business — payment processing systems.


This is a highly business-oriented role. Payments are at the core of the company’s growth, and the stability, correctness, and scalability of this system have a direct impact on business results.


Location: Fully remote (Poland) 🌎 or Łódź (Poland)


Tech stack: Kotlin / Java, PostgreSQL, Kafka, AWS


Your everyday playground:

  • Building backend features end-to-end — from clarifying business needs, through implementation and testing, to production.

  • Working on real payment flows that are used every day and have a direct business impact.

  • Cooperating with Product, other teams, and external partners to shape solutions together.

  • Taking responsibility fort he quality and stability of systems running in production.

  • Developing, integrating, and improving existing systems.

  • Reviewing code and supporting teammates as part of a collaborative team.

  • Working with technical and business documentation and turning it into working solutions.

  • Running functional and manual tests of different card payment scenarios, including certification-related checks.


* The role combines software development and domain-focused work — roughly 50% development and 50% documentation, testing, and certification-related activities.


What are we looking for? 🕵️‍♀️

  • Strong backend experience with Kotlin or Java (4+ years), including building and maintaining production systems.

  • Solid understanding of relational databases and asynchronous, event-driven architectures.

  • Ability to work independently with incomplete and evolving requirements, asking the right questions along the way.

  • Strong sense of ownership and responsibility for what goes to production.

  • Hands-on, critical mindset — you think through problems and solutions, not just implement tickets.


Bonus points:

  • Experience with payment, fintech, or other regulated systems.

  • Familiarity with PCI DSS–compliant environments or end-to-end certification processes (e.g. EMV L3).

  • Knowledge of Spring WebFlux and Kotlin Coroutines.


Why join us? 🌟

  • At DNA Technology, we believe in clear communication - we regularly talk about what works and what doesn’t, and how we can make things better (not just in code).

  • Your development is extremely important to us! You can count on individual growth sessions to support you on your unique professional journey.

  • We don’t do layers of management. Everyone has a voice and real influence on how we work.



Sounds like a fit? Let’s talk! 🚀