LONDON :Starling Group has signed a 10-year agreement to upgrade core software at Tangerine, a Canadian digital bank owned by Bank of Nova Scotia, as the British-based bank continues its global expansion, Starling said on Tuesday. The deal is the biggest yet for the British digital bank's Engine by Starling software services subsidiary, and will see Tangerine migrate its digital banking operations to Engine's cloud-based Software-as-a-Service platform. The partnership follows Engine’s expansion