Charlie Brooker has stated that the lack of futuristic elements was intentional, and he wanted to do an episode that is Black Mirror-y but occurs in the present.
On the smart display at Smithereen headquarters, there is a mention of Prime Minister Callow from The National Anthem (2011).
Andrew Scott can't drive in real life, so they had to put the car on a 'giant skateboard' as Scott described it on The Graham Norton Show (2007).
While waiting at Smithereen, a location shown on the pickup app is named Bandersnatch Theatre from Black Mirror: Bandersnatch (2018).
While waiting at Smithereen, a location shown on the pickup app is on Skillane Street. Victoria Skillane is the focus of White Bear (2013).