Senior .NET Developer

Looking for more than just a job? Join a vibrant community of developers who collaborate, learn, and grow together while working on diverse and inspiring .NET projects. Our recruiters work closely with you to find the perfect match based on your skills and career ambitions. We currently have several exciting opportunities open, including projects for well-known global players in telecommunications and life sciences, giving you a chance to contribute to solutions that truly matter. As a Great Place to Work, we value continuous learning, transparency, and teamwork, bringing together over 7,300 IT professionals across multiple countries. Here, your ideas and growth are always welcomed — become part of a place where your impact goes beyond code.

Your responsibilities

• Build and evolve scalable, cloud-ready .NET applications that deliver real value to users while maintaining high standards of code quality and performance

• Design and implement modern APIs and microservices in collaboration with cross-functional teams, fostering a shared sense of ownership and innovation

• Actively participate in agile ceremonies and contribute ideas that improve processes, quality, and team dynamics

• Drive automation by creating and maintaining CI/CD pipelines, automated tests, and infrastructure-as-code to ensure smooth and reliable deployments

• Join our vibrant .NET community within the company, share your knowledge, learn from experienced peers, and grow your expertise in a supportive environment

Our requirements

• Minimum 5 years of professional experience in .NET development with strong proficiency in C# and .NET Core

• Practical experience with cloud platforms such as Microsoft Azure or AWS, including deployment and monitoring

• Solid understanding of software architecture, design patterns, and best practices in object-oriented programming

• Hands-on experience with DevOps tools and practices, including CI/CD pipelines, containerization with Docker, and Infrastructure as Code (e.g., Terraform or ARM templates)

• Excellent command of English, both written and spoken, for effective collaboration in international teams

What we offer

• Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas

• Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market

• We share the profit with Workers - over PLN 60M has already been allocated for this aim since 2022

• Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more

• Comfortable workplace – class A offices or remote work

• Dozens of fascinating projects for prestigious brands from all over the world – you can change them thanks to Job Changer application

• PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers

• Investment in your growth – meetups, webinars, training platform and technology blog – you choose

• Fantastic atmosphere created by all Sii Power People

Recruitment stages

1. Send your CV

2. Talk to us about your expectations

3. Learn more about our projects and choose the best

4. Start your adventure with Sii!

Sii Sp. z o.o.

Sii is the leading technology consulting, digital transformation, engineering, and business services vendor in Poland. We already employ more than 7 500 professionals and implement projects in a variety of industries for clients from many countries around the world.

The Great Place to Work title, won 10 times in a row, proves that at Sii we create a friendly work environment. In a survey, as many as 90% of our employees responded that Sii is a great place to work, and 95% of them think we have a great atmosphere here.