Songfacts®:

• On August 20, 2016, Architects' lead guitarist and primary songwriter Tom Searle passed away after a three-year battle with skin cancer (melanoma). This was the first song to be released by the band following the loss of their founding member.
  
  Drummer Dan Searle told Revolver that his brother had begun work on the track before his death, but was it was ultimately finished by his band mates posthumously. "Completing it for him was a massive responsibility," he said.
• Dan Searle's lyrics address the death of his brother viewing it as both the ending of their world, but also acknowledges it as a new beginning for the band.
  
  They say the good die young
  No use in saying "what is done is done"
  'Cause it's not enough
  And when the night gives way
  It's like a brand new doomsday
• This was voted by the readers of Kerrang as their song of the year for 2017.
• Originally dropped as a standalone single on September 7, 2017, "Doomsday" was included on Architects eighth studio album Holy Hell, which was released the following year.