A pioneering Consultant General Surgeon specializing in Upper Gastrointestinal (UGI) and Obesity (Bariatric and Metabolic) surgery, Assoc. Prof. Dato' Dr. Nik Ritza Kosai Nik Mahmood established Malaysia's premier UGI and Bariatrics referral center. He has performed over 1500 bariatric surgeries, the highest in Malaysia, and is renowned for minimally invasive techniques, including single-incision laparoscopic surgery. A key opinion leader, he holds leadership roles in national and international surgical societies and has over 100 publications. His patient care philosophy emphasizes tailored and precise treatment.