SoloQ
External Mythic+ matchmaking for World of Warcraft.
SoloQ is a web service paired with an in-game addon that matches WoW players into dungeon groups. You queue up with your character, and the matchmaker builds a balanced group by role, score, and key level.
The addon-to-web bridge
WoW addons can't make HTTP calls. So the addon encodes the player's profile as a base64url token with an Adler32 checksum, and the player copy-pastes it into the web app. Matched groups come back the same way. The same encoding is implemented in both Lua (addon) and C# (server).
Matchmaking
The queue lives in Redis, and the API stays stateless, so queue state is shared rather than held in one process. The matchmaker runs a set of rules to build groups: role composition, score range, key level compatibility. When a group forms, every member is notified in real time over SignalR.
Verification
Player profiles are verified against the Blizzard API. This prevents people from faking their score or key level. The API data is cached to stay within rate limits.
Why it's interesting
The technical challenge here is the bridge between two runtimes that can't talk to each other directly. The copy-paste token approach is a workaround for a platform limitation, but it works reliably and the checksumming catches corruption.