I reached out to the recruiter via LinkedIn in October.

She liked my resume and sent a Frontend Assignment which had to be done within a specific deadline.

Assignment Submission:
The frontend assignment was to enhance a React-based invoice app by adding Redux and more features.
I submitted it before the deadline.

1 Week after submission, I got a call from HR for the Technical interview.
The Interview was scheduled for the next day.

Technical Interview:
I was asked to explain the features I had implemented using Redux.
I explained to him everything.

One additional question he asked:
Implement copy to a new invoice from existing invoice functionality

My approach:
When someone presses the copy invoice button, they will be redirected to the '/new' route but with a ?id=x parameter. We will write a useEffect checking if parameter id is present or not. If present, it will get the invoice with that particular id from the redux store and populate the data. else it won't do anything.
I can help you rewrite the text to make it clearer and correct any spelling, grammar, and punctuation errors. Here's the revised version:

During the interview, the interviewer was very impressed with my approach, profile, internships, and projects. We also had some healthy discussions about Functional and Class-based components and many other stuff.
I was confident that I would get the internship.

However, a week went by, and I did not hear anything from them. I decided to call the HR representative and she promised to let me know by tonight. Unfortunately, I did not receive any response.
Some days back, I checked their LinkedIn page and discovered that they had hired some interns. I am not sure what went wrong and where I went wrong.