Company Description Lumen Solutions Group Inc. is a technology consulting Services company based in Florida. We provide a wide array of experienced business and IT professionals supporting clients from solution design to implementation and support. We specialize in professional IT consulting services, IT Staffing, Business/IT Strategy, Business Process Blueprints, Enterprise Architecture, Enterprise Transformation. Role: Senior Developer – Mainframe / Assembler (z/OS, TPF) Location: Remote or NEC Region Job Type: Long Term Contract Job Summary: Client is seeking a Senior Developer with deep experience in IBM z/OS mainframe environments, specifically working with Assembly language and C/C++. The developer will support and enhance a critical legacy application primarily written in Assembler, while also contributing to system integrations and new service development. This role requires strong experience working with mainframe-based transportation or enterprise systems, along with the ability to analyze complex systems and design integration solutions across multiple platforms. Primary Responsibilities Enhance and maintain an existing mission-critical mainframe application written primarily in Assembler. Perform system analysis and propose technical design solutions. Develop and maintain components in Assembler and C/C++. Design and implement integrations between legacy systems and enterprise services. Develop and support API integrations as both a producer and consumer. Work with messaging systems such as IBM MQ. Build and maintain file-based integrations including SFTP-based data exchanges. Support database interactions with DB2. Collaborate with architecture and engineering teams to modernize and extend legacy systems. Required Technical Skills Mainframe Environment IBM z/OS Experience with TPF-based systems. Programming Languages Assembly (Primary language) C C++ Integration Technologies Experience working with enterprise integrations such as: DB2 databases REST or enterprise APIs IBM MQ messaging File-based integrations SFTP data transfers Developmental Responsibilities Legacy system enhancements. Integration design and implementation. New service/component development. System troubleshooting and debugging. Lumen Solutions Group Inc is an equal opportunity employer. All qualified applicants will be considered for employment without regard to any legally protected status.