Real-time Planning Poker with Socket.IO

Real-time sounds complicated until you draw the right events. In Sprint Deck, everything revolves around rooms and a handful of well-defined messages.

# The events

The rule that saved me: the server is the source of truth. The client only emits intentions and reacts to the state that comes back.

socket.on("vote:cast", ({ user, card }) => {
  room.votes[user] = card
  io.to(room.id).emit("room:state", serialize(room))
})

# Consensus

When everyone has voted, I compute the mode and the deviation to show whether the team is aligned or it’s worth a discussion.

Good real-time is the kind you don’t even notice: the screen is just always right.

The result is a table that feels like magic, but it’s really just a good event contract.