Key insight: Fiserv has signed a deal with Sumitomo Mitsui Card Company to sell payments technology to Japanese merchants. What's at stake: The bank technology seller is recovering from a recent earning slump. Forward look: Japan's government is pushing digital payments, creating an opportunity for payment technology companies. Three months after posting an earnings miss that analysts said was "difficult to comprehend," Fiserv has reached a deal with Sumitomo Mitsui Card Company that enables the bank techno ...