Modern Web App with Teams Integration

I need a web application built from scratch with a modern, minimalist interface. The core of the project is a data-driven workflow that does four things smoothly: gathers structured input from users, pushes and pulls data to and from Excel workbooks, posts automated or ad-hoc messages into Microsoft Teams channels, and layers in AI integration for smarter insights and actions.

Here is the functional scope I have in mind:
• User Interface – sleek, responsive, and modern and minimalist, accessible on desktop and mobile.
• Data Handling – forms or tables that capture, validate, and store information in a database while keeping an always-in-sync link with specific Excel sheets.
• Microsoft Teams Integration – ability to authenticate, choose a channel, and send formatted messages or notifications based on user actions or scheduled events.
• AI Integration – embed an AI model or connect to an API so we can, for example, summarise data, generate suggested replies, or surface predictive metrics inside the app.

Tech stack is flexible as long as it supports the above (React, Next.js, Node, Python, or similar). If you have a preferred low-code approach that still meets these requirements, I’m open to it.

Acceptance criteria
1. Deployed app reachable via a secure URL.
2. UI passes a quick usability test on Chrome and Edge.
3. Excel sync performs CRUD operations without data mismatch.
4. Teams messages post with correct formatting and timestamps.
5. AI feature produces consistent, verifiable output for a provided sample dataset.

Please share a concise outline of your approach, any similar projects you’ve delivered, and a rough timeline for getting from kickoff to first live version.