Avankia Senior Java Developer interview questions

The interview had 2 rounds, first was HR round and second one was technical discussion where I have to share my computer screen. Mr Raman Shrivastava asked question on core java and how you will implement arraylist. I answered all the question and even the implementation of arraylist was correct. He showed positive feedback but later on when I connected with HR, she said they weren't satisfied. I don't know whether they really want to hire.