John Donovan, as AT&T’s head of networks and then chief of the Communications business unit, has had a profound impact on the telco’s technology strategy, supply chains and public perception. He masterminded the Domain 2.0 program to reinvent the supplier relationships around software-defined networking (SDN), and oversaw the strategy to virtualize network elements as aggressively as possible, so far on track to hit the target of virtualizing 75% of network functions by 2020. In a restructuring last year, following the acquisition of Time Warner, AT&T split into four major business units – Communications, run by Donovan; Latin America (headed by Lori Lee); Advertising and Analytics (run by Brian Lesser); and WarnerMedia (the renamed Time Warner, headed by John Stankey). Donovan’s…