Stuart Shanahan has been selling since the start of his career.  The Dubliner recalls early jobs selling everything from fire extinguishers to door handles before a role opened up at PayPoint, a FTSE 250-listed payments company that had expanded to Ireland. Shanahan worked his way up from a sales executive to head of PayPoint, a company known for its in-shop terminals that let customers pay bills and transfer money, in the years following the financial crisis. “It was completely random; I just happened upon the job. I didn’t even know what I was applying for, and I ended up in…