FK Duel

A competitive football trivia game in English and Turkish. Duel another player live — grid, bidding, teammate-chain and penalty modes among others — with a rating per mode, or play offline against bots. Player data comes from Wikipedia and Wikidata.

One Swift package holds the rules, sessions, bots and Elo, shared by the Vapor server and the iOS app. Play is server-authoritative over WebSockets, with full state snapshots, acknowledged moves, a reconnect grace period and rating-based matchmaking that falls back to clearly-labelled bots. A load test of 200 concurrent players peaked at 216 MB with about 5 ms p99 move latency. The same game core compiles to WebAssembly for a browser version, shrunk from 55 MB to 13.8 MB by dropping ICU. Much of it was built with Claude, with decisions recorded for my review.