Sir David spent his 40-year career in healthcare management and leadership and was awarded a knighthood in the 2017 New Year’s honours list in recognition of his services to the NHS.

David joined the NHS in 1983 and his final position in the NHS was as Chief Operating Officer on the Board of NHS England, overseeing the health and care of 56 million people and the budget of £180 billion.

In 2022, David was named by the Health Service Journal as the fourth-most influential person in English health policy in their HSJ100 list.

In between times, his roles included chief executive of NHS Haringey and chief executive of the Whittington Hospital NHS Trust after which he joined the Royal Free London (RFL) in July 2009. He led the hospital to foundation status in 2012, followed by the successful acquisition of Barnet and Chase Farm hospitals in 2014. During his tenure the trust was awarded the Dr Fosters NHS Hospital of the Year and was accredited as a Global Digital Exemplar. After a decade at RFL, he left to take up the position of NHS regional director for London, with an oversight of the healthcare of a population of 10 million and a budget to £18 billion. He led the NHS in London through the first waves of Covid-19, before moving on the national COO role, where he led England through subsequent waves of Covid.