QAT Global, a US-based IT consulting firm with more than 30 years in the market, is hiring a Sr. Mainframe Assembler & COBOL Developer to join an international project supporting a US client in the life insurance industry. This professional will work directly with client stakeholders in the US and collaborate with distributed teams across Brazil, Costa Rica, and the United States, contributing to the maintenance, enhancement, and migration of critical mainframe-based insurance administration systems.Main Challenges:Maintain and enhance legacy mainframe systems written in Assembler and COBOL, working with VSAM file structuresSupport and develop applications on the Ingenium platform (COBOL/DB2)Troubleshoot and resolve production issues across multiple mainframe environmentsSupport ongoing data extraction and migration efforts toward a third-party administrator (TPA)Collaborate with cross-functional teams to ensure system reliability, performance, and continuityProvide knowledge transfer and documentation to preserve institutional knowledgeRequired Experience:Strong professional experience in mainframe development experience with COBOL (critical)Hands-on experience with IBM Mainframe Assembler programming on z/OSProven background in life insurance or annuities systems (policy administration, claims, or billing)Experience working with VSAM file structures on mainframe environmentsHands-on experience with DB2 on IBM mainframeStrong troubleshooting and problem-solving skills in legacy/production environmentsAbility to work and communicate effectively in English with US-based client teamsPreferred Background:Familiarity with Ingenium or similar insurance administration platformsExperience with data migration or system conversion projectsExposure to CICS Transaction Gateway and Unix environmentsBS/MS in Computer Science, Systems Analysis, Computer Engineering, or equivalentThis role is especially relevant for professionals who have worked in life insurance mainframe environments, supported legacy system modernization, and are comfortable taking ownership of a broad range of responsibilities in a direct, fast-paced team culture.