How would you design a price tracking website like camelcamelcamel.com?\n\nFor example, we might want the following behavior. Input: Item URL and target price. Result: if the item goes below the target price, then users tracking the item will get an email alert.\n\nConsider the following topics in the answer: database design (SQL or NoSQL), automated price checking mechanism, price scraping or price API, caching data.

How would you design a price tracking website like camelcamelcamel.com?\n\nFor example, we might want the following behavior. Input: Item URL and target price. 