API exposes REST JSON. Frontend calls with fetch/HttpClient, sends Authorization header, handles 401 by refresh/login. ShopNest React cart calls GET /api/cart and POST /api/orders on the ASP.NET Core API.
Infosys rounds often probe: Enterprise .NET.
Themes commonly reported in public MNC interview experiences (AmbitionBox / LinkedIn / Glassdoor-style). Practice aloud; keep answers this short in the real round.