.NET Developer

Senior • Hybrid

$110 - $150/

Warsaw, Poland

💻 .NET Developer

💰 B2B , salary range flexible

🌍 Hybrid – Warsaw, Puławska 182 (1/2 days from the office)

About N7 Mobile

N7 Mobile is a close-knit, 18-year-strong boutique software house that builds mission-critical systems for some of the biggest financial, payment, and fintech players in Europe.

We’re expanding one of our flagship long-term teams with an experienced .NET engineer who will take real ownership of a brand-new, high-impact backend component – a standalone, long-running service built in .NET 8+ and shipped in Docker, running both in the cloud and directly on customer premises.

Stability, clean architecture, and smooth deployment experience are everything here.

💡 Key Responsibilities

Design and deliver a rock-solid Background/Worker Service in .NET 8+
Build a production-ready Dockerized component (cloud + on-premise deployments)
Keep code quality, testability, and long-term maintainability at the highest level
Actively drive development with GitHub Copilot, we expect ~50% of the code to be AI-assisted
Own CI/CD pipelines (GitHub Actions)
Perform thorough code reviews and continuously raise the team’s engineering bar
Collaborate daily with the rest of the dev team (English is the working language)

Requirements

Deep, production-grade expertise in C# and .NET 8+
Proven track record shipping long-running services (Worker Service / IHostedService) in Docker
Strong grasp of background service architecture (channels, resilience, observability, Polly, etc.)
Fluent with Git + GitHub Actions workflows
Real daily experience using GitHub Copilot (or similar AI tools) and great prompting skills
Clean code, SOLID, and modern patterns (DDD/CQRS appreciated) are second nature to you
Solid spoken and written English (B2+ or higher) – daily technical discussions
Bonus points: background in financial systems, fiscalization, or POS solutions

Recruitment process – just 3 short stages

Quick HR call (expectations & logistics)
Technical interview with the team
Project deep-dive call – mostly for you to get to know us and the project inside out

If you enjoy small, senior-heavy teams where decisions are made fast and your opinion truly matters, this is the place.

We’re looking exactly for you. Apply now! 🚀

N7 Mobile Sp. z o.o.

N7 Mobile Sp. z o.o. is a boutique software house with 18 years of experience, specializing in building mission-critical systems for major financial, payment, and fintech companies in Europe. The company is known for its close-knit team and senior-heavy environment, where fast decision-making and valuing individual opinions are key aspects. N7 Mobile emphasizes stability, clean architecture, and smooth deployment experiences in its projects. The company operates in a hybrid model with a presence in Warsaw, Poland, and focuses on delivering high-quality, maintainable software solutions.