Feature Flag and its use in Software Testing

Hi this is Palak Sharma

I am in final year of my engineering. And I like doing coding in Python programming languages. Campus interview in also near and for this I and my team is developing a software. I am researching about various aspect for developing a software. I also heard about Feature Flag, that is most urgent for software testing. I am little bit confused about it how it can be use in Software testing, when we should use it during software development process.

Hoping for some positive response.