State Street Corp. has installed Spiros Giannaros as the chief executive of Charles River Development, the Burlington-based investment software provider that it acquired in 2018 for $2.6 billion. Giannaros came to State Street about a year ago from the British financial data firm IHS Markit Ltd. He has served as Charles River's president since December. The move was a homecoming for Giannaros, who worked at Charles River from 1999 to 2014 when it was still an independent company. He is replacing John Plansky in the CEO role. Plansky isn't going anywhere: He's global head of State Street AlphaSM, the company's comprehensive software platform that got its start with the Charles River acquisition two years ago. Giannaros reports to Plansky.