How to build a mobile barcode scanner that retrieves product prices from a custom API (similar to Scan2Info)?

I’m working on a system similar to Scan2Info, where users can scan a product barcode using their mobile phone camera and instantly retrieve product information such as price, name, and details from a custom backend API.

My goal is to replace traditional shelf price tags and allow customers to query prices themselves by scanning barcodes.

Here’s what I’m trying to achieve:

Use the mobile camera to scan barcodes (EAN/UPC) Send the scanned code to a backend API Retrieve product data from a database (SQL Server) Display the result instantly on the mobile screen

My current stack:

Backend: ASP.NET Core (using ADO.NET) Database: SQL Server Frontend: considering Blazor or a simple web-based solution

My questions:

What is the best library or approach for barcode scanning in mobile browsers (JavaScript-based)?

Is it better to build this as a PWA or a native mobile app?

How can I optimize the response time for near real-time results?

Are there recommended architectures for scaling this kind of system?

Any advice, tools, or real-world would be appreciated.