I'm not sure the article did well answering the headline. I now know that there is a mainframe (emulator it seems from additional research) that returns API res

I'm not sure the article did well answering the headline. I now know that there is a mainframe (emulator it seems from additional research) that returns API responses very quickly (1-6ms) TO a Java app... which apparently is inefficient as the page render takes 6-10 seconds. Interesting problems not terribly well described in the post, would love to read more.