When tenants first walk into their new apartment at the Brandon Place complex in Oklahoma City, they aren’t likely to notice anything out of the ordinary for 2019—there are smart locks on the door with keycode entry, and contemporary thermostats with LCD touch screens. During their move-in briefing, they’re told the unit’s smart systems can be operated from Amazon.com Inc.’s AMZN -2.27% Alexa-powered devices. But they aren’t told how hard Amazon worked to get those devices into their new home.