Is it possible to have an SEO friendly Express.js Web site?

If Express provides a traditional route structure (i.e. http://yoursite.com/foo), will the pages show up on Google's Search Engine Results Page, similar to say a Wordpress blog or PHP Web site using the same path structure?

What is your ressource? IMHO your information is wrong. The Url can be uses for some merge logical data.

This has nothing to do with caching, that has much to do with the response headers of your webserver:

  • Etag: a tag for identifying if the content has changed
  • Last-Modified: a way to check if the content has changed in the meantime
  • Expires: the time how long the page should be cached without recontacting the server again.

For more details see also wikipedia or the RFC2616.