I disagree most vehemently with the widespread and longstanding notion that characters are "built" from page to page to page. If that were true, it would mean the reader starts on page one of a story with a completely vapid and vacant character, a blank slate, that will be "built" up over the course of the narrative, and then finally, upon the last word, we have a fully formed, deeply imagined character. At the beginning of the story was a flat slab of concrete; at the end, there's a beautiful mansion. I'm not sure I want to spend twenty pages with a character who's slowly but surely being pieced together before my eyes.
On the other hand, if characters are revealed instead of built, if, say, we start with a complicated knot of a character on page one and we get closer and closer to her as the story progresses, then I'm hooked. Again, maybe this is semantics, but I don't think so. I think of characters as being swaddled in layers and layers of winter clothes when we meet them on the first page of the story, and with each turned page, with each scene the reader spends with them, the characters peel off another piece of clothing. A scarf, a glove, a jacket, a shirt, and on and on. Finally, if the writer's done the work, when we get to the end of the story we'll see the characters in their most vulnerable, naked, and perfect state. All will have been revealed, and we'll know the character as God knows them, better than they know themselves.