Since 2021, Irwin has freelanced as a content writer, publishing numerous articles and blogs on a wide variety of topics related to his career as a healthcare professional, as well as discussions about contemporary consumer, business, travel, financial, lifestyle, and cultural issues. Previously, Irwin was the health science writer and quality advisor at COLA Resources, Inc. a non-profit company that provided educational and consulting services for the medical laboratory profession. He was a regular contributor to the Quality Advisor Blog for Advance Magazine, as well as other professional publications including Physician's Office Resource (POR), Medical Laboratory Observer (MLO), and Clinical Laboratory Products (CLP). He also served as a laboratory surveyor and technical consultant with the Commission on Laboratory Accreditation. Earlier in his career, Irwin was CEO of Community Response, an NGO supporting HIV/AIDS clients in Chicago, and co-chaired the Cook County HIV/AIDS Advisory Board. He also served as Director of Education for the Health Education and Resources Organization (HERO) in Baltimore. His background includes managing the clinical laboratory at Crittenden Regional Hospital in Arkansas and providing technical consulting services to regional laboratories in the Mississippi Delta.