The Mainframe Software Engineer will be responsible for developing, maintaining, and enhancing Mainframe applications. The role will involve performing impact analysis and code modifications, as well as designing and executing unit and integration testing. The engineer will analyze production incidents and perform resolutions while supporting both batch and online processing systems. The role also requires collaboration with distributed teams and architects, participation in modernization initiatives, implementation of automation and DevOps practices where applicable, and assistance with migration and integration with modern technologies.