Trivia: Minor Spoilers: Director David Leitch previously made "Deadpool 2," which starred Ryan Reynolds, and in which Brad Pitt had a brief, blink-and-you'll-miss-it 2-second cameo. Leitch also directed this film, which stars Brad Pitt, and in which Ryan Reynolds has a brief, blink-and-you'll-miss-it 2-second cameo. (Reynolds appears very briefly in a flashback as the assassin Pitt is subbing for).
Trivia: Just an interesting contrast and parallel... Director David Leitch previously made "Deadpool 2," which had a character named Domino who had the superpower of having amazing luck. Things would just work out for her. "Bullet Train" is almost the opposite. In this movie, Brad Pitt's Ladybug mentions throughout that he has terrible luck, and this reflected by absurd and awful things happening to and around him frequently. (Although he does have flashes of good luck here and there).
Trivia: Minor Spoilers: It is revealed at the end that Ladybug's handler is played by Sandra Bullock in a cameo. (Her voice is heard throughout the film, but she doesn't appear onscreen until the final scene.) Originally, the role was meant to be played by Lady Gaga in a cameo. However, scheduling conflicts with "House of Gucci" made this impossible.