In a screening I was asked to write a code for tcp connection supporting multiple clients.
The code works, but my code was rejected because it wasn't efficient.
I don't see how we can help you since you didn't provide any details and/or code.
"Any fool can write code that a computer can understand. Good programmers write code that humans can understand." --- Martin Fowler
Please correct my English.
For my next trick, I'll need the help of a tiny ad ...
a bit of art, as a gift, that will fit in a stocking