Exactly -- see my other comment here: https://news.ycombinator.com/item?id=42850693 https://news.ycombinator.com/item?id=42850693 I did this as the front-end

Exactly -- see my other comment here: https://news.ycombinator.com/item?id=42850693 https://news.ycombinator.com/item?id=42850693 I did this as the front-end engineer of a high-profile site that went live well before XMLHTTPRequest.