We are specialists in **technological transformation**, combining human expertise with AI to create scalable tech solutions. With more than 8,000 CI&Ters worldwide, we have already partnered with over 1,000 clients throughout our 30-year history. Artificial Intelligence is our reality. **Important**: If you reside in the Campinas Metropolitan Region, your presence at our city offices is mandatory, per our current attendance policy. We are looking for a Mainframe Developer with solid COBOL experience and comprehensive knowledge of CICS, DB2, JCL, TSO, VSAM, change management tools (e.g., Changeman), and debugging/analysis tools. This person will directly contribute to legacy system modernization, migration, and decommissioning initiatives—from discovery (legacy understanding) through safe removal of components and routines. We seek someone with an analytical mindset, autonomy, strong communication skills, and the ability to collaborate with multidisciplinary teams (business, architecture, engineering, operations, and QA), ensuring secure and high-quality transitions. **Responsibilities:** * Conduct legacy discovery: understand workflows, map business rules, and document components (programs, copybooks, JCLs, DB2 tables, VSAM files, and CICS transactions). * Perform impact and dependency analysis to support the migration/modernization plan. * Implement adjustments to the legacy system for stabilization and decoupling when required, enabling phased migration. * Execute and support regression testing, debugging, and fixes (online and batch), ensuring stability during transition. * Support transition strategies such as parallel execution (dual-run), result validation/reconciliation, and cutover preparation. * Lead decommissioning activities: removal of jobs, routines, transactions, datasets, and integrations—ensuring evidence, traceability, and risk mitigation. * Produce and maintain relevant technical/functional documentation for auditing, support, and knowledge transfer. **Requirements:** * Proven COBOL experience in mainframe environments. * Solid knowledge of CICS, DB2, JCL, TSO, and VSAM. * Experience with change management tools (e.g., Changeman) and debugging/analysis tools. * Ability to perform investigative analysis (troubleshooting), identify root causes, and propose solutions with a systemic view. * Strong verbal and written communication skills for interaction with technical teams and stakeholders. * Ability to work autonomously, organize effectively, and collaborate within teams. **Preferred Qualifications:** * Prior experience in legacy modernization/migration (refactoring, replatforming, rehosting, strangler pattern, dual-run, etc.). * Experience mapping integrations (services, messaging, files/batches, data exchange routines). * Knowledge of quality and reliability practices (observability, metrics, incident management). * Use of supporting tools (including AI) to accelerate documentation, summarization of workflows/code, test case generation, and analytical support—with human technical validation. #LI-RR2 Midsenior **Our benefits:** * Health and dental insurance; * Meal and food allowances; * Childcare assistance; * Extended parental leave; * Partnerships with gyms and health & wellness professionals via Wellhub (Gympass) TotalPass; * Profit and Results Sharing Program (PLR); * Life insurance; * Continuous learning platform (CI&T University); * Discount club; * Free online platform dedicated to promoting physical, mental, and overall well-being; * Pregnancy and responsible parenting course; * Partnerships with online course platforms; * Language learning platform; * And many more More details about our benefits here: https://ciandt.com/br/en-us/careers At CI&T, inclusion starts from the first contact. If you are a person with a disability, it is important to **submit your medical report during the selection process.** *Check which information must be included in the report* *by clicking here.* This way, we can ensure the support and accommodations you deserve. **If you do not yet have the qualifying medical report, don’t worry—we can help you obtain it.** We have a dedicated Health and Wellness team, inclusion specialists, and affinity groups ready to support you at every stage. Count on us to walk this journey alongside you.