what are the things that we need to consider for better application performance
Discussion posts and replies are publicly visible
This is a very broad question. There are a lot of small things you can do in different parts of your application to improve performance such as how often you query data on an interface or how much looping you might do in a process. Do you have a more specific question? Appian already takes care of most performance concerns under the hood so that developers don't need to think about it.