Dr Guevara graduated with a Bachelor of Science (BS) and minor in Chemistry from Duke University in the United States in 2005. He then moved to Sydney and obtained his Bachelor of Medicine/Bachelor of Surgery (MBBS) from the University of Sydney in 2010. He obtained his Master of Surgery (MS) from the University of Sydney in 2013. He completed his General Surgery training at Liverpool Hospital, St George Hospital, Prince of Wales Hospital, Campbelltown Hospital, as well as multiple regional centres. He became a Fellow of the Royal Australasian College of Surgeons (FRACS) in 2019. He undertook two years of intensive fellowship training in Breast, Endocrine and Head & Neck surgery at St George Hospital.

He has been published in the ANZ Journal of Surgery and has had multiple presentations in the Royal Australasian College of Surgeons (RACS) Annual Scientific Conference.

He currently holds appointments at: 

- Strathfield Private Hospital

- St George Private Hospital

- Liverpool Hospital