Senior Mainframe Developer (COBOL, PL/I, JCL, DB2, CICS, IMS) (m/f/d)

You ensure that proven mainframe systems remain stable and high-performing – while also bringing them into the modern IT landscape. You future‑proof legacy COBOL applications, optimize processes, and gradually transform systems into modern, Java‑based architectures. Your expertise makes legacy burdens disappear without compromising stability. Working model: Primarily remote work with occasional travel to Germany, depending on project needs.

Developing: With your technical expertise, you design and enhance applications on the mainframe, for example in COBOL or PL/I. New business requirements are implemented into existing systems, while ensuring seamless integration into established system landscapes. Maintaining: Through your analytical skills, existing mainframe applications are continuously improved and stabilized. This includes analyzing issues in live operations, resolving errors, and optimizing programs for performance and reliability. Modernizing: With your experience, you analyze legacy applications as part of modernization initiatives. You contribute to transforming and evolving existing systems toward future-ready architectures. Migrating: Using your know-how, COBOL-based applications are migrated to modern technologies such as Java. Program logic is adapted and refactored for new target platforms, ensuring functional equivalence after migration. Ensuring quality: With a structured approach, tests are executed and results documented. You maintain clear documentation of applications, changes, and migration steps, and support the creation of technical concepts. Collaborating: In close alignment with business departments, architects, and developers, you contribute to project teams focused on further development and modernization of the system landscape.

Qualification: Solid experience in developing applications on mainframe systems, ideally IBM z/OS. Expertise: Strong knowledge of COBOL and/or PL/I, including maintenance and enhancement of existing applications Technology: Hands-on experience with common mainframe technologies such as JCL, DB2, CICS, CTG, IMS, or comparable components Modernization: Experience or interest in Java development and modern frameworks is beneficial. Knowledge of legacy modernization, especially COBOL-to-Java transformation, is a plus Architecture: Understanding of system architectures and their integration into modern IT landscapes. Tooling: Experience with version control, as well as build and deployment processes Methods: Analytical skills for evaluating applications and system landscapes. Familiarity with software development methodologies, whether agile or traditional Documentation & Testing: Experience in creating technical documentation and concepts, as well as in test procedures Languages: German at least C1 level, English at least A2 level Your personality Analytical: You think in structures and get to the core of complex problems quickly. Collaborative: You communicate clearly and work smoothly with different teams and stakeholders. Reliable: You take ownership, work independently, and stay open to new technologies and approaches. #LI-Hybrid #LI-CS1