title: Cache invalidation using the query-string, bad practice?
body: <p>On websites I make I usually invalidate the cache of CSS and JS using query-string params, like so:</p>
  
  <p><img src="https://up.kibakoapp.com/Ry4IghMQtH!#direct" alt="Image"></p>
  
  <p><em>Note: this is a screenshot from the chrome inspector, these query-strings are all appended automatically by a little system I made when being rendered into the browser.</em></p>
  
  <p>A friend now told me that using the query-string doesn't cache as good as changing the filename itself or somewhere in the path before the filename. He also sent <a href="http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/" rel="nofollow noreferrer">an article along with</a> it and here they're mainly talking about bad performance when people use proxies.</p>
  
  <p>However, the article is 8 years old. I wonder, is it still a valid point? Should I care? Is it really a bad practice?</p>