Live Collectibles Auction Platform

An online auction house runs live bidding events for collectible items. During an event each bidder's browser must hold an open two-way connection so that price changes are pushed out to every participant the moment they happen, without any client polling. The team wants nothing to size or patch, per-request billing, and a handler that runs only for the length of each message while scaling from dozens of participants to tens of thousands in seconds. Bidders sign in with an email address and password before joining, and every accepted bid is written to a durable relational store kept for seven years of regulatory audit. The current high bid and the ranking of bids per lot must be held in memory, updated with atomic counters and sorted structures, and published to subscribed handlers.