{
  "context": "A developer needs to implement protection against last-second bidding in a PubNub auction platform. When bids arrive near the end of an auction, the system should extend the auction duration to give other bidders a chance to respond.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Threshold window check",
      "description": "Calculates remaining time and checks whether the bid arrived within a configurable threshold window before the auction end time",
      "max_score": 15
    },
    {
      "name": "Time extension logic",
      "description": "Extends the auction endTime by a configurable number of seconds (autoExtendSeconds, default 30) when a bid falls within the threshold",
      "max_score": 15
    },
    {
      "name": "Extension count tracking",
      "description": "Increments an extensionCount field on the auction state each time an extension occurs",
      "max_score": 15
    },
    {
      "name": "Max extensions limit",
      "description": "Enforces a maxExtensions limit (default around 20) and stops extending once that limit is reached",
      "max_score": 15
    },
    {
      "name": "Hard duration cap",
      "description": "Enforces a maxTotalDurationHours hard stop that prevents extensions beyond a maximum total auction duration regardless of extension count",
      "max_score": 10
    },
    {
      "name": "Extension broadcast",
      "description": "Publishes an 'auction_extended' message to the auction channel with the new end time and remaining time",
      "max_score": 15
    },
    {
      "name": "Extension number in event",
      "description": "The auction_extended broadcast message includes the extensionNumber so clients know how many extensions have occurred",
      "max_score": 5
    },
    {
      "name": "State persistence",
      "description": "Updated endTime and extensionCount are persisted back to KV Store auction state",
      "max_score": 10
    }
  ]
}