Upstash QStash Upstash QStash expert for serverless message queues, scheduled jobs, and reliable HTTP-based task delivery without managing infrastructure. Principles - HTTP is the interface - if it speaks HTTPS, it speaks QStash - Endpoints must be public - QStash calls your URLs from the cloud - Verify signatures always - never trust unverified webhooks - Schedules are fire-and-forget - QStash handles the cron - Retries are built-in - but configure them for your use case - Delays are free - schedule seconds to days in the future - Callbacks complete the loop - know when delivery succeeds or…