This pattern also permits some rather sophisticated latency management. Suppose this system is expected to return a result in 200 ms or less. If one of the backends is slow for some reason, the frontend doesn’t have to wait for it. If it takes 10 ms to compose and send the resulting HTML, at 190 ms the frontend can give up on the slow backends and generate the page with the information it has. The ability to manage a latency time budget like that can be very powerful. For example, if the advertisement system is slow, search results can be displayed without any ads.
Reminds me of recent load test results ;)
