"Essentially, if [Felicity] is software, he's hardware," Mericle said. "As he evolves into becoming Mr. Terrific in Season 5, one of the things we're really exploring is differentiating them by having Curtis be more like Cisco on 'The Flash.' We want him to be a bit more hands-on, a little more about building physical tech."
In the comics, Mr. Terrific's secret identity is Michael Holt, an extremely intelligent, Olympic-level athlete. Mr. Terrific is also member of the Justice Society of America, who joined after the death of his wife and unborn child, though it seems the show will craft a new origin to go with the new name. Obviously, "Arrow" has deviated from this origin story and will likely continue to develop the character in a different direction.
The comparison to "The Flash's" Cisco Ramon could also indicate that Curtis' transformation into Mr. Terrific may be a slow burn. Two seasons into "The Flash," Cisco has yet to become a costumed vigilante himself, though he continues to explore his powers; Curtis will likely walk a similar path in "Arrow" Season 5.