The Royal Academy of Engineering held a series of seminars on the Philosophy of Engineering in 2007, to which this author contributed a paper entitled “Philosophical Issues in the Practice of Engineering Design”. This considered this essential feature of engineering, which is to apply scientific methods to produce products created to meet human needs by ensuring their realisation obey relevant theories to achieve practical ends. This is done by a design practice which has not received the same level of philosophical enquiry that has been addressed to the pure or “natural” sciences or even engineering analysis and the research associated with that practice. While the 2007 paper is reviewed in the light of almost two decades of further research into the most demanding of engineering design practice – that of physically large and complex systems (exemplified by certain marine vessels, large civil engineering constructions and major chemical plant) – it has been observed that the practice of such design has itself grown in complexity. From considerations of design philosophy, including quite contrary visions, design at this demanding level encompasses the creation of not just technological products but also organisations, processes, environments and even ways of thinking. Thus, the practice of engineering design is very much a human endeavour that is largely conducted by teams of engineers, often of different sub-disciplines interacting with non-engineering stakeholders. With the onset of AI and Machine Learning how this Computer Aided Design practice is likely to change is seen as a philosophical and sociological question.