This seems to be really hard to do unless you're using global cdn and forgoing https. Ping between US and SG is almost 300ms in the best condition. That alone a

This seems to be really hard to do unless you're using global cdn and forgoing https. Ping between US and SG is almost 300ms in the best condition. That alone already blew the 100ms budget for visitors far away from your server location. And then we have https, where initial https handshake alone could take several hundreds ms (depending on various reasons).