DualDev is a real-time 1v1 coding battle platform — two developers, same problem, live timer. What makes it different: → Opponent Silhouette — see your opponent's code structure masked as ▓▓▓ blocks. Spot if they're using a hashmap or brute force, without seeing their actual code. → AI Judge — evaluates both solutions at match end on correctness, efficiency, and code quality. → ELO matchmaking — rated queue with topic & difficulty filters, plus friend rooms.