Following his graduation from Harvard Medical School, Dr. Weinstein did a residency, chief residency, and fellowship in pediatric endocrinology at Boston Children's Hospital. He subsequently obtained a Masters in Clinical Investigation from Harvard and MIT, and became Director of the Glycogen Storage Disease Program at Boston Children's. In 2005, Dr. Weinstein moved to the University of Florida where he directed the GSD Program and became a tenured professor. He moved to the University of Connecticut in 2017 where his team launched the world’s first gene therapy trial for glycogen storage disease. In 2020, he left the academic world to serve as the medical lead for the GM1 gangliosidosis and metachromatic leukodystrophy gene therapy trials at Passage Bio. He subsequently served as acting Chief Medical Officer for Grace Science, LLC leading the submission of the IND for gene therapy for NGLY1 deficiency, and he remains a consultant for rare disease trials.

In 1989, he was named as one of the inaugural Goldwater Scholars. He is a former Jan Albrecht Award winner from the American Association for the Study of Liver Diseases, and he was the George Sacher Award winner from the Gerontological Society of America. In 2013, Dr. Weinstein was knighted in Poland and honored with the Order of the Smile international humanitarian award.