Hey,
If you are planning for applying in Amazon make sure you are doing good with programming languages .
You need to be good at Data Structure algorithms and they will check your basics as well as knowledge in depth.
Being good in languages means you need to skilled enough because they ask really tricky questions so it will be better if you are good in java and have done some project in it, so that you sound good while answering technical terms.
Be good with your communication skills so they will come to know that you are good to go with the team.