The premise of this series is partly based on the true story that broke in 2010 of a cell of Russian Sleeper agents who had been "hiding in plain sight" in the United States for decades. Several of them had had children, coworkers, friends, and neighbors who all had no idea that they were spies. These agents were ultimately returned to Russia in a trade for some Americans who were being held by Russia.
Joseph Weisberg created the show. Weisberg worked in the CIA's directorate of operations from 1990 to 1994. As a former agent, any script written by Weisberg must go in front of the CIA Publications Review Board.
In real life, Annet Mahendru speaks 6 languages (German, English, Russian, French, Persian and Hindi) due to a nomadic upbringing all across the globe. She joked that she was hired because the producers thought she was an actual spy.