Conor O’Kelly makes his way through the throngs between the main stage of the Web Summit and its four vast pavilion halls. Thankfully, the chief executive of the National Treasury Management Agency (NTMA) is not too difficult to spot – a former rugby number eight, O’Kelly stands at a commanding 6ft 5in. The senior public servant is in Lisbon to meet co-investors and potential partners, as well as to listen to various sessions on big investment themes – from green tech, to artificial intelligence to robotics. “I am here because this is an incredible event,” O’Kelly tells me. “For me,…