Discussion on Bookmyshow's server capability

We seldom get asked this question about how do we ensure a highly efficient and robust platform/system that can cater to large number of hits.

Well, Bookmyshow's server was down for the starting 4 mins with a 504. How could they have improved the services to make sure this didnt happen ?

Is it pre allocating high performance cloud resources started up and then switched to at 12PM or having multiple regions to divert and split the huge incoming traffic ?

What are your thoughts ?

I know this is also a more of a System Design scenario, would love to hear people's advice on this.

PS. Unfortunately I didnt get a ticket despite having a 10K queue number. Since by the time I got option to select the blocks, and 2 seats - there were only few blocks left and the seats present in the block were at opposite ends - so had to go back select a different block and there also it so happened to be the case.