In data science education, a major challenge is ensuring fair and consistent assessment grading while providing timely feedback to large numbers of students. The rising demand for quality education has increased the burden on educators to evaluate various types of assessments without overwhelming workloads. Generative AI (GenAI) has become valuable in creating tests, rubrics, and grading, but its full potential is limited by the lack of integration in popular Learning Management Systems (LMS) like Canvas and Moodle. SM Grader (www.smgrader.com) is a cloud-based platform that addresses this by offering GenAI-powered grading, supporting multiple assessment formats, and providing detailed feedback. Successfully trialled with over 2000 students, it integrates with LMS platforms, offers custom grading rubrics, and detects cheating, helping educators manage assessments more efficiently and fairly.