Question: Both the single "Stay" and the debut studio album "Cloud Nine" were developed by which Norwegian DJ and record producer?

Related documents: [0]  [DOC] Cloud Nine (Cloud IX) is the debut studio album by Norwegian DJ and record producer Kygo and features the likes of Maty Noyes, Conrad, Parson James, Tom Odell, Foxes, Matt Corby, RHODES, Will Heard, Julia Michaels, James Vincent McMorrow, Kodaline, Labrinth, John Legend and Angus & Julia Stone. It was released on 13 May 2016 by Sony Music and Ultra Music. [END] 
[1]  [DOC] "Stay" is a song by Norwegian DJ and record producer Kygo, featuring American singer Maty Noyes. The song was produced by Kygo with fellow Norwegian, William Wiik Larsen, who also wrote it with Noyes. It was released as the fourth single from Kygo's debut studio album, "Cloud Nine" (2016). An official music video for the song was released on 18 February 2016. [END]  
Answer: Kygo
Kygo