As a leetcoder for more than 2 years, I have struggled from how to understand the challenge to how to solve the challenge. I want to write down some of my thoughts here.

Till now, when I open some challenges with medium label, I still think they are 'hard' to me and it is really frastrating.
When I register contest every week and find I cannot solve the questions, it frastrates me again.
Something frastates me most is when I took interviews, not all the interviews I met would like to ask me write white-board solution to solve an quesion on leetcode. The few interviewers who satisfied with my coding answers would like to go further -- I was asked to show my engineering skill. HS!

By now, do you think the essence of leetcoder is frustrated people? Not exactly. In my own view, I am happy when I solve the questions with python and found my code beat 100%. Otherwise, I would fork the sample submission beating 100% and improved the effiency to make it faster. Mainly my happiness is linked with the speed of my solution. The faster my code run, happier I am.

In the past 2 years, I am used to repeat clicking a question, repeat coding/testing and debugging and submitting, repeat copying/pastng and improving others' solutions. Repeat again, again and again.

That is what I think the essence of leetcoder -- the essence of leetcoder is repeater.