Full-Stack Product Engineer (Kotlin/React)

If you enjoy working closely with the business, interacting with real users, and shaping a product from end to end, this role offers an unusually high level of influence, responsibility, and visibility.

We are rebuilding and modernizing the tool that sits at the heart of our client's operations. You’ll help us evolve a legacy system into a scalable, maintainable platform while shipping meaningful features.

Rate: 140–180 PLN + VAT (B2B) per hour.

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

Tech stack: Kotlin, Spring Boot, React 17, Node 16, Tailwind (migration), PostgreSQL, AWS (EC2 → ECS), Terraform/Terragrunt, Datadog.

Your everyday playground:

• Work directly with Support Agents and stakeholders.

• Build and maintain product features across Kotlin/Spring Boot and React/Node.js.

• Modernize and refactor parts of a legacy monolith while keeping the system stable for daily operations.

• Investigate issues across domains: map processes, trace data flows, propose pragmatic fixes.

• Integrate the back office with other internal systems.

• Collaborate with the Tech Lead and engineering teams while having autonomy to deliver end-to-end solutions.

• Operate in AWS-based infrastructure, use Datadog for observability, and work with PostgreSQL as the primary database.

What are we looking for? 🕵️‍♀️

• 4+ years of experience as a Full-Stack Engineer.

• Strong communication skills (feeling comfortable working directly with users and clarifying ambiguous input).

• Solid backend engineering experience (Kotlin preferred, but Java is fine!)

• Some frontend engineering experience (React).

• Openness to stepping into unfamiliar tech, especially on the frontend when needed.

• Ability to operate autonomously: once a goal is set, you can figure out the delivery path.

Bonus points:

• Experience in payments, financial systems, settlements or operational tools.

Why join us? 🌟

• Massive ownership & impact: you directly shape how the team operates every day.

• Engineering meets product: rare opportunity to code, design, decide, and talk to real users.

• A small, empowered team: you influence technical decisions, processes, and priorities.

• Safe-to-fail environment: experiments are encouraged, and internal users give fast feedback.

Sounds like a fit? Let’s talk! 🚀