WhatsApp Marketing Web Portal Development

Overview
I need a lightweight web portal built that lets me upload a CSV or Excel file of contacts, review and map the data, and launch personalized WhatsApp campaigns through my already-linked 360Dialog WhatsApp Business API account. The portal should also show delivery status and incoming replies in one place.
Scope of Work

Contact Import: Accept CSV/Excel upload, validate phone numbers, and map custom columns (e.g. name, and other personalization fields) to a contact list.
Campaign Sending: Use a pre-approved, ready-made WhatsApp template to send personalized messages via the 360Dialog API, merging in the mapped fields for each recipient.
Delivery & Replies Dashboard: Simple view showing send status per contact (delivered/failed with reason) and any replies received.
Hosting: Deploy on Render (free tier is fine) for simplicity and low cost.
Documentation: Short README covering redeployment steps and how to update/edit templates.

What I'll Provide

Active 360Dialog account and API key
WhatsApp sender number
Sample contact file for building/testing upload and mapping logic
Pre-approved campaign template (ready-made, standard format)

Tech Stack
Open to Python, Node.js, or PHP — whichever gets to a stable, production-ready result fastest.
Definition of Done
A test campaign (~50 contacts) sends successfully through the portal, with the dashboard correctly showing delivery status and failed-number reasons for each recipient.
Timeline
I'm looking for a fast turnaround — ideally a working version within a day.