In June 2015, he co-wrote and produced The Weeknd's "Can't Feel My Face", which peaked at number one on the Billboard Hot 100. Martin co-wrote and produced two other songs from The Weeknd's sophomore album, Beauty Behind the Madness (2015), namely "In the Night" and "Shameless", as well as four songs from The Weeknd's third album, Starboy (2016). He also worked on The Weeknd's fourth studio album, After Hours (2020), contributing five compositions, "Hardest to Love", "Scared to Live", "Blinding Lights", "In Your Eyes", and "Save Your Tears". The album was both a critical and commercial success.
In January 2015, he co-wrote and co-produced Ellie Goulding's "Love Me like You Do", which reached number 3 on the Billboard Hot 100, while also producing several songs from her album Delirium including the hit single "On My Mind", which was released on 17 September 2015.
In July 2015, Martin produced Demi Lovato's song "Cool for the Summer" which reached number 11 on the Billboard Hot 100. He also contributed to "Confident" and "For You" from her fifth studio album Confident.
In November 2015, Adele's album 25 was released and Martin co-wrote and co-produced the record's third single "Send My Love (To Your New Lover)" with Shellback, and would eventually become a top 10 hit in the US and the UK.