Filming in Berlin proved very difficult as the city was undergoing its coldest winter in 20 years at the time.
Olivier Schneider, the actor who played Smith (the assassin with the glasses), was also a stunt coordinator for this film. He was also the stunt coordinator for 96 Hours (2008), which also starred Liam Neeson.
The first of four collaborations between actor Liam Neeson and director Jaume Collet-Serra. They would reunite for Non-Stop (2014), Run All Night (2015), and The Commuter (2018).
The working title was "Unknown White Male".