I've been preparing for a long time (mostly inconsistently) but I have a hang of the data structures and algorithms (except advanced types like max flow, ford-fulkerson etc...) and have solved many problems (currently solved ~ 640+).

Still have not cracked Google/Amazon. Got rejected in the Google onsite and got rejected in Amazon bar raiser, which was the last interview in the process I had. I had apprehension initially during interviews but slowly got over it and started attending lot of interviews. Before this Google/Amazon rejection, got rejected in VMWare, Indeed, BrowserStack, Dream11 and a few more. Literally I lost count. All the above in the Onsite rounds.

I can't figure out why I'm unable to get an offer? Is it the way that I'm speaking? Or the way I'm approaching the problems? Or the way I stop once a solution is reached (be it optimal or not) without discussing whether that was the best solution or not? I have no idea what I'm doing wrong and now I'm getting frustrated. It's been too long (since 2015) and I just want to get into a company which I want to be the last.

Reading all the offer posts just makes feel like a worthless $h!t for a while but end up picking up myself and start preparing again. Now this has become so habitual that I'm unconciously doing this and practically stuck in a loop. I started this post as way to ask the community on what could be the reason I got rejected and ended up venting out and feeling bad.

After some brief introspection, I have come up with some points why I might have not yet cracked the onsites.

1. Once a solution is reached, I fail to stop and discuss whether that's the best I can do or I can improve the solution with some tradeoffs. Even if that's the best solution, I fail to state that indeed it is the best for the given constraints.
2. In the amazon bar raiser, the interviewer asked binary search based question. I explained the logic, time complexity and then coded the solution. But instead returning left, I returned left+1. So may be, I got rejected in the correctness and writing bug-free code criteria.

Please feel free to bash me or add more specific points or general points that might help me structure my approach in the interviews.