Software Engineer (C# + Mainframe) w Gdańsk, Polska

For our client, a global IT services company specialising in managing and modernising business‑critical systems and platforms for enterprise customers (including cloud, mainframe and hybrid environments), we are looking for a Software Engineer with strong experience in C# and IMS (mainframe). You will be responsible for supporting and driving the modernisation of an existing mainframe system, contributing to the transformation of legacy architecture into more scalable and maintainable solutions, while collaborating with international teams in an English‑speaking environment. Key responsibilities Design, develop and maintain components of a legacy mainframe system with a focus on modernisation initiatives Work with C# and IMS technologies to enhance and extend existing system functionalities Participate in system transformation efforts, including refactoring and integration with modern platforms Collaborate with architects, developers and stakeholders to define technical solutions aligned with business needs Analyse existing code and propose improvements to increase performance, stability and scalability Support troubleshooting and debugging in production and non‑production environments Ideal candidate profile Strong experience as a Software Engineer working with C# and mainframe environments (IMS) Solid understanding of legacy system architectures and modernisation approaches Experience in working with enterprise‑level systems and complex integrations Good command of English (B2+/C1), enabling effective communication in an international environment Ability to work collaboratively in distributed teams and communicate with both technical and non‑technical stakeholders Conditions Work model: fully remote Start: ASAP Project duration: initially 7 months, with the possibility of extension Employment type: B2B contract via KUBO Salary: it depends on your experience Benefits: life insurance, private healthcare, Multisport card, and development support (including co‑funding of certifications) Recruitment steps Initial call with a KUBO recruiter Interview(s) with the client Decision, feedback and support through offer and onboarding