# Legacy & mainframe modernisation Analysing, reconstructing and gradually replacing COBOL and PL/I estates – without putting operations at risk. ## Technologies and methods - **Mainframe & legacy:** COBOL, PL/I, JCL, CICS, VSAM, IBM Db2, z/OS, Reverse engineering, Legacy reconstruction ## Industries - Banking: Cloud migration and core system modernisation under supervisory requirements. - Insurance: Replacing legacy policy systems and securely integrating new digital services. ## Four phases with clear deliverables - Phase 1: Analysis. System landscape, dependencies and regulatory frame as a solid baseline. - Phase 2: Design. Target picture, architecture and delivery plan with milestones, risks and compliance controls. - Phase 3: Delivery. Iterative, automated and measurable – together with your teams. - Phase 4: Handover. Stable operations, complete documentation and enabled teams. All twelve services are listed in the [services](https://www.klein.business/en/services/) overview; a short [request](https://www.klein.business/en/contact/) is enough for a first conversation. ## Frequently asked questions ### How does a collaboration start? With a short [request](https://www.klein.business/en/contact/). We reply within two working days with a proposal for a no-obligation first conversation. Last updated: 2026-11-11 --- Source: