Conceptionista is the lexical combination (see 'portmanteau') of the words Concept, which is a general idea, or something conceived in the mind, and Sandinista, a Nicaraguan authoritarian political party.
Despite recent attempts to make this term more popular it must be noted that its etymology is rather new.
Conceptionistas simply look at Concept Development as an Art, their own brains as the canvas, and the ideas they develop along the way are simply the masterpieces.
Person 1:"Wow! Did you see this brilliant new App?"
Person 2:"Oh yeah, that creator must be a real conceptionista!"