Sammy Kam Chi-sum, the primary architect of Hong Kong’s contactless Octopus cards, is retiring after nearly 30 years with the company at the end of this month, before what he says is an inevitable transition to a technology that will not even require tapping for certain transactions. Octopus’ chief operations officer began his journey in 1995 when he joined the MTR Corporation’s marketing team to help launch what would become the world’s first contactless system that revolutionised public...