Many developers use localhost environments (often with tools like Ngrok) to build and test their Shopify apps. This setup works well for development purposes, allowing you to interact with the Shopify API without needing a public-facing server (Stack Overflow), (Shopify Community). However, it’s limited to local testing and has some downsides like handling webhooks, which require a public URL to function correctly. Shopify also requires webhooks for real-time updates (e.g., orders, inventory) to have a secure, public URL. Since localhost isn’t accessible from the web, you need to host your app on a public server with SSL enabled to receive and handle these webhooks correctly (Shopify). It’s better to deploy it to a cloud or dedicated server like AWS or Google Cloud, Heroku or DigitalOcean. They can handle extensibility, scalability, security, and reliability far better than a localhost setup (DEV Community).