Senior Software Developer .NET

Paessler AG; Kraków; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

International team

Job summary

Paessler AG is seeking a Senior Software Developer to shape the future of our network monitoring software. You will own architecture and ensure code quality in a small, agile team, collaborating with product management to turn ideas into robust features.

We offer room to grow, exposure to AI/ML and Rust, and a structured onboarding in an international environment. Expect cross‑platform backend work on Linux/Windows with modern .NET, CI/CD, and strong data integration.

Qualifications

• 6+ years of software engineering on the .NET platform with C# mastery.
• Deep experience with .NET Core 9+ and high-performance patterns.
• Strong track record in designing and debugging distributed, high-concurrency systems.
• Cross-platform development across Linux and Windows.
• Solid SQL and schema design, data integration in enterprise environments.
• Proficiency in frontend basics: TypeScript, JavaScript, HTML.
• CI/CD with Docker and GitLab; Jira in workflows.
• Experience with AI-assisted coding tools to accelerate delivery.

Responsibilities

• Design, build, and maintain resilient backend services and cross‑platform applications.
• Architect distributed systems using modern patterns and Clean Code.
• Integrate SQL and time-series databases into core architecture.
• Leverage AI tools within the development lifecycle for observability and diagnostics.
• Collaborate with product manager and team using GitLab, Jira workflows.
• Contribute to code reviews and knowledge transfer within a small agile team.

Skills

C#/.NET

Modern .NET Stack

Distributed systems

Cross-platform (Linux/Windows)

SQL & DB integration

Frontend basics (TypeScript/JS/HTML)

CI/CD & Docker

AI-assisted coding tools

Tools

Docker

GitLab CI/CD

Jira

Git

Job description

Are you an experienced .NET developer who wants to shape the future of network monitoring software used by IT teams around the world? Our PRTG Core Team is looking for a Senior Software Developer to help us plan, build, and modernize the features our enterprise customers rely on every day. Working within a small, agile team, you'll take ownership of architecture and code quality, share your expertise through code reviews and knowledge transfer, and collaborate closely with our product manager to bring your own ideas to life. As part of Paessler, you'll also have plenty of room to grow, explore new technologies like AI/ML and Rust, and enjoy a structured onboarding into an enthusiastic, international team.

YOUR TASKS

• Design, build, and maintain resilient backend services and cross-platform applications supporting Linux, Windows, and macOS.
• Architect distributed systems following modern software architecture, Clean Code principles, and proven design patterns.
• Integrate traditional relational databases and high-performance time-series databases into the core product architecture.
• Leverage modern AI tools within the development lifecycle and explore AI/ML integrations for system observability and automated diagnostics.
• Collaborate across the full lifecycle using modern Git-based workflows, GitLab CI/CD pipelines, and Jira.
• Learn the inner workings of specialized network and IoT monitoring systems to contribute to core domain engineering.

YOUR PROFILE

Must-Have Qualifications & Core Skills

• Experience Level: 6+ years of software engineering experience on the .NET platform with deep mastery of C#.
• Modern .NET Stack: Extensive experience with .NET Core 9+, utilizing current platform capabilities and high-performance paradigms.
• Distributed Systems: Solid track record designing, building, and debugging complex, high-concurrency distributed systems.
• Cross-Platform Engineering: Hands-on experience developing and deploying services across Linux and Windows (macOS environment experience is a plus).
• Databases & Data Integration: Strong knowledge of SQL, schema design, query optimization, and enterprise database integration.
• Full-Stack / Web Foundations: Proficiency in modern frontend technologies including TypeScript, JavaScript, and HTML.
• Containers & CI/CD: Solid experience with Docker, containerized workflows, Git, and automated CI/CD practices (GitLab, Jira).
• AI-Assisted Engineering: Demonstrated experience or active engagement with AI-driven coding tools (e.g., GitHub Copilot, Cursor, LLM-based tools) to accelerate software delivery.

Nice-to-Have Qualifications

• Orchestration & Cloud: Hands-on experience with Kubernetes (k8s) and public cloud deployment patterns (AWS/Azure/GCP).
• Domain Experience: Background in network infrastructure, network monitoring, or IoT sensor data ingestion systems.
• Specialized Storage: Familiarity with high-throughput Time-Series Databases (e.g., InfluxDB, TimescaleDB, QuestDB).
• System-Level Languages: Production experience with Rust, or a strong willingness to learn and apply Rust where ultra-low latency or explicit memory control is needed.
• AI/ML Integration: Hands-on experience embedding AI/ML frameworks or models into enterprise backend workflows.

Soft Skills & Working Style

• Strong technical leadership, analytical thinking, and a pragmatic problem-solving mindset.
• Commitment to code quality through peer reviews, automated testing, and clean design.
  Enthusiasm for learning domain-specific protocols and deep network/IoT domain internals.

FACTS FOR YOU

• Many possibilities to further develop your individual skillset
• Innovative and creative work environment with plenty of room for new ideas
• A structured onboarding phase withexperienced colleagues
• Flexible working hours and a family-friendly environment
• Permanent employment contract
• A great working atmosphere in an enthusiastic international team with flat hierarchies
• Paessler is a fast-growing midsized company that has been in the market for 20 years. The company is focused on long-term goals and is currently comprised of 400+ employees

And at the end, a very important note: For us, diversity is more than just a word - it's a commitment. Our job posts are geared towards all people, regardless of their gender, sexual orientation, background, faith, or physical abilities. We value diversity and strive to create a work environment that prioritizes equal opportunities and inclusion. In line with this objective, please note that candidates with severe disabilities will be given preferential consideration over applicants with equal qualifications. At Paessler, we're determined to break down barriers and provide everyone with the chance to develop their full potential. Please feel free to let us know if you believe there are ways we can improve the wording of our jobs posts or our overall recruitment approach. Let's work together to create a more colorful and inclusive corporate culture!