Node.js Backend Developer / Full Stack Developer for a written spec of a notifications service

Hi, my marketplace is already live on a Laravel and Vue stack and I am not changing that core. What I need is small and very specific: a short written spec for a separate little service that handles real-time notifications to buyers and sellers, plus the Stripe and webhook events my Laravel app handles awkwardly today. I have been told this kind of side-service is usually built in Node, so it can run next to the marketplace without touching the main app. I am not technical, so I want a senior node.js backend developer - ideally a full stack developer who also understands how a service like this plugs into an existing Laravel and Vue app - to write down how it should work before anyone builds it. This is a focused one-off, not a big project. In 1-2 pages I want a clear view on: - What the standalone Node service should own vs what stays in the Laravel app - How notifications reach buyers and sellers in real time without overloading my current setup - How to receive Stripe and other webhooks reliably, with retries, so nothing is missed - Where this service reads my existing MySQL data and where it should keep its own - A short note on hosting and what it costs to run something this small I just need a clean 1-2 page written note I can hand to my developer - no call needed, and I am not looking to start a long engagement off this, just this one document. The marketplace already exists, so specifics about the current data model and integrations will be shared only with the person I sign with, after NDA. I will not share specifics before contract. To apply, please share 2-3 production Node services you have shipped, and your fixed price for this short write-up.