Senior Software Developer .NET

Paessler GmbH; Kraków; On-site; PLN 240,000 - 400,000; Full time

Benefits offered by this job

Skill development opportunities

Innovative work environment

Structured onboarding

Flexible working hours

Permanent employment contract

International team with flat hierarch"

Job summary

Paessler GmbH is seeking an experienced senior software engineer to design, build, and maintain resilient backend services and cross-platform applications that run on Linux, Windows, and macOS. You will work on architecture, performance, and reliability.

The role emphasizes distributed systems design, integration of relational and time-series databases, and the use of modern DevOps practices. You will experiment with AI-assisted coding tools, participate in code reviews, and collaborate across

Qualifications

• 10+ years of software engineering on the .NET platform.
• Extensive experience with .NET Core 9+.
• Proven track record in designing high-concurrency distributed systems.
• Experience developing services across Linux and Windows.
• Strong SQL, schema design, and data integration.
• Frontend skills with TypeScript, JavaScript, and HTML.
• Experience with Docker, containerized workflows, GitLab, and Jira.
• Experience with AI-powered coding tools.

Responsibilities

• Design, build, and maintain backend services and cross-platform apps.
• Architect distributed systems using modern patterns and Clean Code principles.
• Integrate relational databases and time-series databases into core product architecture.
• Explore AI/ML integrations for observability and automated diagnostics.
• Collaborate across the lifecycle using Git-based workflows, GitLab CI/CD, and Jira.
• Learn the inner workings of network and IoT monitoring systems.

Skills

10+ years .NET

.NET Core 9+

Distributed systems

Cross-platform

SQL / Data integration

Frontend basics

Docker & CI/CD

AI-assisted coding

Tools

Kubernetes

GitLab

Jira

Git

Job description

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: 10+ 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 with experienced 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!