Question: Which profession do Daron Malakian and Samuel Aroutiounian have in common?

Context articles: Rebellion (song)
Lonely Day
Vartan Malakian
Lynch the Weirdo
System of a Down
Samuel Aroutiounian
Scars on Broadway
Steal This Album!
Daron Malakian
Scars on Broadway (album)

"Rebellion" is a song by American rock band Linkin Park.
 The song was originally recorded by the band for their sixth studio album, "The Hunting Party", where it appears as the eighth track on the album.
 The song features Armenian-American multi-instrumentalist Daron Malakian from rock band System of a Down, who plays additional guitar on the track.
 The track was released as second promotional single from "The Hunting Party" on June 4, 2014 and was later released as the fourth official single from the album on October 13, 2014, and was included on American rock radio.
"Lonely Day" is the second single from the 2005 album "Hypnotize" by Armenian American metal band System of a Down.
 It was written by guitarist Daron Malakian, who also provides lead vocals on the track.
 The song received a nomination for Best Hard Rock Performance at the 49th Annual Grammy Awards.
Vartan Malakian (Armenian: Վարդան Մալաքյան, born February 14, 1947) is an artist and painter.
 He is the father of Daron Malakian, guitarist co-founder of System of a Down and Scars on Broadway.
 He was born on February 14, 1947 in Mosul, Iraq.
Lynch The Weirdo is the title of the second full-length album by the metal band Bad Acid Trip, released on April 20, 2004.
 It was produced by System of a Down member Daron Malakian.
System of a Down, sometimes shortened to System and abbreviated as SOAD, is an Armenian-American heavy metal band from Glendale, California, formed in 1994.
 The band currently consists of Serj Tankian (lead vocals, keyboards), Daron Malakian (vocals, guitar), Shavo Odadjian (bass, backing vocals) and John Dolmayan (drums).
Samuel Aroutounian (Russian: Сэм Арутюнян; born September 17, 1976) is an American producer who serves as the president of Creative Talent Management
Scars on Broadway was an American rock band, founded by System of a Down member Daron Malakian.
 The band's eponymous debut album was released on July 29, 2008.
Steal This Album!
 is the third studio album by Armenian American rock band System of a Down, released on November 26, 2002, on American Recordings.
 The album was produced by Rick Rubin and Daron Malakian, and reached #15 in the "Billboard" Top 200.
Daron Vartan Malakian (Armenian: Տարօն/Տարոն Վարդան Մալաքեան, born July 18, 1975) is an Armenian–American singer-songwriter, multi-instrumentalist, and record producer.
 He is best known as the guitarist, songwriter and second vocalist of the rock band System of a Down and as the lead vocalist, lead guitarist and songwriter of the band Scars on Broadway.
 Like the rest of the Hollywood-based band System of a Down, he is of Armenian ancestry, but he is the only member to have been born in the United States.
 Daron Malakian is known for his distinctive playing and is ranked 40th in Loudwire's list of "Top 50 Hard Rock + Metal Guitarists Of All Time" and #11 in MusicRadar's poll, "The 20 Greatest Metal Guitarists Ever".
 He is placed 30th in Guitar World's List of The 100 Greatest Heavy Metal Guitarists of All Time.
Scars on Broadway is the only studio album by Scars on Broadway, a band consisting of System of a Down members Daron Malakian and John Dolmayan.
 The album contains fifteen tracks, all written by Malakian.