Justin is a Consultant and Professional Lead for Speech and Language Therapy (SLT) at the Royal Marsden NHS Foundation Trust (RM) in London. He is also a senior member of the Applied Health Research Group and leads the survivorship theme for the International Centre for Recurrent head and Neck Cancer (IReC) at RM. From 2016-2026, he established and led a dedicated SLT service at Imperial College Healthcare NHS Trust supporting the National Centre for Airway Reconstruction and complex laryngology service. He is a Professor of Practice in Speech and Swallowing Rehabilitation in the Department of Surgery and Cancer at Imperial College London.

Justin has been an investigator on several research studies, including NIHR portfolio studies. He is chief investigator on the NIHR-funded CONSIDER Study. He has published extensively and contributed to key policy and position papers, acting as an expert adviser to several national organisations. He was the Allied Health Professions Council Member for the British Association of Head and Neck Oncologists and is currently SLT Council Member for the British Laryngological Association. He is President of the UK Swallowing Research Group. Justin was awarded the Fellowship of the Royal College of Speech and Language Therapists in 2018 and an MBE in the 2022 Queen's New Year's Honours in recognition of his contribution to the SLT profession.