Senior/Lead .NET Developer (f/m/x)

Cooperation with international players across sectors, including automotive, banking, finance, hi-tech, medical, retail, logistics, and public services. The diversity of industries ensures the stability of the company and gives employees the opportunity to develop in various directions.

We deliver projects in many technologies and areas, from software development, through testing, engineering, IT infrastructure, cloud solutions, cybersecurity. We have partnerships with key tech solution providers, like: Microsoft, SAP, Adobe, Salesforce, AWS, Google Cloud, Atlassian.

We began as a one-person start-up in 2006 and grew into a 7 500 workers company in 2025, generating revenue of of PLN 2.2BN, having no debts.

We offer the possibility of working completely remotely, if the position allows it.

We are a key partner for many prestigious global companies from different sectors i.a: BNP Paribas, KUKA, ING or Bombardier with whom we have contracts that guarantee continuity of employment for our workers.  

Since 2018, we have been recognized with the Great Place to Work Europe title, a prestigious award based on employees feedback. According to the study, over 90% of people working at Sii consider it a fantastic place to work.

At Sii we have a lot of knowledge sharing initiatives – our workers can join technology Communities, participate in a mentoring program or benefit from in-house trainings, blog and e-learning platforms.

No matter our title, we address each other by first names. Transparency and dialogue are important for us, that’s why we periodically organize local CEO meetups, online CEO live sessions and departmental Inspiration Days. During them everyone has the opportunity to meet with people managing the company, ask questions, report problems and discuss troubling issues.