Melanie Weisner is a professional poker player. She is also known by her PokerStars online screen name Callisto 5. Weisner transitioned from amateur to professional poker while she was studying musical theater at New York University. Weisner was ranked #1 for heads-up tournament players, and won Player of the Year in the heads-up division on the European Poker Tour. In addition to playing high-stakes cash games and tournaments on the international circuit, she coaches players at a variety of skill levels.