SAP ABAP (Advanced Business Application Programming) is a programming language used to develop reports and business application programs and platforms. As a home-based SAP ABAP developer, your responsibilities include writing code, ensuring client networks and virtual environments remain free from bugs or errors, iterating versions of programs based on client needs and feedback, and providing clients with documentation and training materials. Your other duties may include ensuring code remains functional through upgrade cycles, providing technical support to users, troubleshooting, and creating completion schedules for development projects.