Frontend System Design
/Intermediate
CORS
Definition
Cross-Origin Resource Sharing is a browser security mechanism that blocks web pages from making HTTP requests to a different domain than the one that served the web page, unless the target server explicitly sends CORS headers.
Explain Like I'm New
If you are on `google.com`, your browser will block any JS trying to secretly fetch data from `yourbank.com`, unless yourbank.com explicitly says 'I allow google.com to talk to me.'
Interview Questions
basic
- What is the core concept of CORS?
- What are the pros and cons of CORS?
intermediate
- How does CORS impact SEO and initial page load times?
- When would you NOT choose to use CORS?
advanced
- How does CORS fit into a heavily scaled microservices architecture?
- What are the security implications of CORS?
trick
- Can you combine CORS with other rendering strategies on the same page?