Peyman Moaadi and Poorna Jagannathan, who play Naz's parents, are 12 and 10 years older, respectively, than Riz Ahmed, who plays Naz.
The character of Naz is supposed to be 23 years old. Riz Ahmed was 34 when he made this mini-series.
John Turturro (top-billed actor) doesn't appear on screen until 1 hour and 4 minutes into the episode.
This was originally meant to star James Gandolfini before his untimely death put paid to that. HBO had originally nixed the project but reconsidered following Gandolfini's passing as a tribute to the actor. Robert De Niro was set to replace him. Scheduling conflicts meant that de Niro had to drop out and was replaced by John Turturro.