HireHive, the recruitment software start-up headed up by the co-founder of Zartis, has been acquired. Cork-based HireHive has been bought by Invincible Software Holdings, a British firm that specialises in investing in software businesses. Writing on LinkedIn, HireHive founder John Dennehy said that the investment will ramp up HireHive’s expansion and that he is moving on from the business. “HireHive has found a great parent company with the resources to scale the company and provide our customers with even better product development and ongoing support. It’s business as usual for the company but personally I’m moving on,” he wrote. No…