Yev from Backblaze here -> You're not going to believe this, but the folks at Evolve used Powerpoint and a template...seriously.

exiftool says it's PowerPoint, surprisingly:

  $ exiftool Build+Book+Backblaze+60+Drive.pdf  | tail -n5 | head -n3
  Title                           : 7400-0283 Rev A OMS Assy Backblaze 60 Drive
  Producer                        : Mac OS X 10.11.3 Quartz PDFContext
  Creator                         : PowerPoint