The production encountered an unusually cold day while filming on the St. Gotthard Pass in Switzerland when it started snowing in August.
The film contains a 4-minute one-take scene because the production only had one night with all extras available. After numerous rehearsals the team did 5 takes until everyone was happy.
Although a number of scenes in the film had been shot earlier 2014 for a short film, the filmmakers re-shot to accommodate for costume changes.
The project was green-lit only three weeks before principal photography with only a treatment in place.