Senior .NET Developer

Summary

We are looking for a Senior .NET Developer to join a cross-functional agile team committed to building the core architecture and infrastructure of our next-generation platform.

This is not just another feature team role. You will be contributing to the foundation of a scalable, cloud-ready system, designed to operate across Windows, Linux, and macOS environments.

You'll work in a modern engineering ecosystem, using technologies such as .NET Core, Docker, Kubernetes, Kafka, Redis, and Ably, as well as evolving current .NET Framework solutions.

Please note: This role follows a hybrid working model and requires onsite attendance at our Kraków/Warsaw office three days per week.

What you'll do

• Designing and developing scalable microservices from the ground up
• Implementing according to architectural and product design documents
• Reverse engineering of current business logic modules
• Modernizing legacy components to meet new business requirements
• Writing clean, maintainable code with a strong focus on quality and testability (TDD)
• Participating in code reviews and driving engineering guidelines
• Collaborating closely with cross-functional teams across product, QA, and DevOps
• Building and maintaining the team's AI tooling — reusable skills, custom agents, MCP servers, and repo instruction files that encode how our platform actually works

What we're looking for

• 6+ years of experience in backend development using .NET / .NET Core
• Hands-on experience building large-scale web-based systems
• Solid understanding of microservices architecture
• Good knowledge of relational databases
• Analytical mindset with strong problem-solving skills
• Ability to work independently while being a reliable teammate
• Continuous learning approach and adaptability to new technologies
• Good written and verbal English communication skills

AI-first engineering (we mean this literally)

Our codebase is too large to hold in your head, so we work with AI agents by default, and we invest in the tooling that makes them accurate here.

We're looking for someone who:

• Uses agentic coding tools daily for real production work — not autocomplete, but delegating multi-step tasks and reviewing the output critically
• Has authored reusable agent tooling: skills, custom subagents, slash commands, MCP servers, hooks, or equivalent — and can talk about what made them work or fail
• Knows how to give an agent the right context, scope a task so it succeeds, and recognize when the output is confidently wrong
• Is interested in improving our AI setup, not just consuming it

If you've built something in this space — a skill, an agent, a tool, a workflow — mention it in your application. We'd rather see that than a certification.

Nice to have

• Experience with Docker and Kubernetes
• Familiarity with TDD and automated testing approaches
• Understanding of event-driven architecture (Kafka, pub/sub patterns)

Compensation Philosophy

We offer a comprehensive pay and benefits package designed to stay competitive in the market, support your wellbeing, and recognise your contribution to our success. Our approach is underpinned by a pay-for-performance belief in rewarding individual impact. Your specific compensation package will be determined by factors such as your skills, experience, qualifications, and location.

Depending on your role and location, you may be eligible for annual bonuses and incentives, health and wellbeing benefits, paid time off, retirement plans, insurance coverage, and other local or statutory benefits.

Specific details about compensation and benefits for this position will be discussed during the recruitment process.

6+ years in backend development using .NET/.NET Core; experience building large-scale web-based systems; solid understanding of microservices architecture; proficiency with relational databases; strong problem-solving skills; ability to work independently and as part of a team; continuous learning approach; good English communication skills. Experience with agentic coding tools and authoring reusable agent tooling is highly valued.