When he summited the first peak, Annapurna I on 23 April 2019, Purja had only locked down 15 percent of the financing he needed, and most of this money had come from remortgaging his own UK house.
Messner appears several times in the film talking about eight-thousanders and what Purja was trying to do; Purja met Messner after suffering a bad fall on Nanga Parbat but Messner gave him encouragement to keep going, with Purja recounting: "He looked into my eyes and said, 'You can do it'. He told me to my face, and he hadn't even seen my climb. When he did the 8000-ers, the whole mountaineering community was against him, but he proved the concept. He did it when the world couldn't see his vision".
14 Peaks: Nothing Is Impossible was compiled from the 100 hours of footage taken by Purja and the Nepalese climbing team from April to October 2019.
During the project, Purja was supported by a rotating team of Nepalese climbers, several of whom are introduced in the film, including Mingma David Sherpa, Geljen Sherpa, Lakpa Dendi Sherpa, and Gesman Tamang, however, only Purja would complete the summit of all 14 eight-thousanders during the film.
The first person to climb the 14 eight-thousanders was Italian climber Reinhold Messner who took 16 years between 1970 and 1986 and completed the feat without the use of supplementary oxygen.