client name - Fission Labs

tell me about yourself?
Arrow and normal function difference
Git pull and git rebase difference
Use of docker
what is Promises
Payment gateway flow , if transaction fails then what will be flow
If there are 3 responses 1]cors error 2] no response 3] 500 then how to debug from backend
what are Streams and how to use
what is Max_pool
how to prevent Dos attack
Put and patch difference
Can we have multiple primary key
Why use index in db
Having vs where
what is coding structure , how to use keys/ naming variables
what is api and rest api