Simple, correct, fast: in that order
When I was in school in the 70's.  (That's NINTEEN seventies.)  There was this book called The Psychology of Computer Programming.  This predates the microcomputer era as we know it.  Punched cards were still common when the book was written.A computer was to control a new assembly line for a car company.  They couldn't get the software to work.  They called in an outside insultant.  The outsider developed a program that worked.  (It was more complex.)  The book was about the psychology part:  The original programmer says: "How fast does YOUR program process a punched card?".  Answer: "About one card per second."  "Ah!" said the original programmner, "but MY program processes ten cards per second!"The outsider said, "Yes, but MY program ACTUALLY WORKS".  If the program doesn't have to work, I could make it read 100 cards per second.Correctness comes first.  Simplicity is highly desirable, adds additional cost, but always comes after correctness.