In 2003, the two were tapped to write a screenplay for what would become their first feature film, Cloudy with a Chance of Meatballs. After a year working on the script, they were fired for story issues and replaced with new Writers, who after a year were also fired. Lord and Miller were then re-hired in 2006. The two completely redid the script, this time with the creative input of their crew. The new draft had the protagonist as a failed Inventor who wanted to prove himself to his town. The two were almost fired again after Amy Pascal, head of Sony, criticized the film for a lack of story. Although the film succeeded on the comedic front in the animatic stage, Pascal cited the lack of an anchoring relationship in the film as a failure in the story telling. Unable to create new characters and environments to suit the new story demands, the two elevated the character of the tackle shop extra to be the protagonist’s father, thereby creating the relationship Pascal had requested. The pair's experience on Cloudy taught them two valuable lessons: the power of creative collaboration and the importance of emotion in a story.

Cloudy with a Chance of Meatballs was released in 2009 to critical and popular acclaim. After the film was released, the two sought to try to make something different from Cloudy and pitched themselves as possible Directors for the 21 Jump Street script that Michael Bacall and Jonah Hill had written. The studio agreed and the two directed their first live-action R-rated film, once again released to critical and popular acclaim which led to the production of a sequel titled 22 Jump Street.

During the production of 21 Jump Street, they pitched a take on a possible Lego film to Dan Lin. Lin and Warner Brothers loved the take, so Lord and Miller wrote and eventually directed their third feature film together, The Lego Movie. The duo were picked by Warner Bros. to write the script for the upcoming superhero film The Flash. The duo were also picked up in 2015 by Sony Pictures to make an animated Spider-Man film with the option to direct.

In November 2017, Lord and Miller commented on their departure from Solo: A Star Wars Story. Lord stated "The experience of shooting the movie was wonderful. We had the most incredible cast and crew and collaborators. [...] We’re really proud of the work we did on the movie and we wish everybody the best.” Miller added "As Phil said, we had such a great relationship with cast and crew, we were really rooting for them. After we took a much-needed vacation, we got back into it and now we’re writing and producing a sequel to The Lego Movie and producing a Miles Morales animated Spider-Man."

In March 2018, it was announced they will receive executive-producer credits on Solo: A Star Wars Story.

Though nothing they pitched made it to air, they produced the pilot to Clone High, which was subsequently dropped by Fox. After they wrote and produced on a series of sitcoms, MTV informed the duo that they were interested in purchasing a 13-episode season of Clone High. Although the show was met with acclaim, MTV canceled the series after hunger strike protests occurred in India over the show’s portrayal of Gandhi as a motor-mouthed partier.