Priority Queue

ELI5 — The Vibe Check

A priority queue is a job queue with a VIP lane. High-priority tasks jump ahead of low-priority ones. Password reset emails? High priority. Weekly newsletter? Low priority. It's like the ER triage system — heart attacks before paper cuts.

Real Talk

A priority queue processes messages based on assigned priority levels rather than strict FIFO ordering. Higher-priority messages are dequeued first, enabling critical tasks to bypass less urgent ones. Implementation varies by system: some use multiple queues per priority level, others use sorted data structures or dedicated priority fields.

Show Me The Code

// BullMQ priority (lower number = higher priority)
await queue.add('password-reset', { userId: 1 }, { priority: 1 });
await queue.add('newsletter', { batch: 500 }, { priority: 10 });
await queue.add('analytics', { event: 'click' }, { priority: 100 });

When You'll Hear This

"Payment confirmations go into the priority queue ahead of marketing emails." / "Use priority queues to ensure critical alerts aren't delayed by bulk jobs."