What's ninja coding actually??
As a developer is it good or bad for his/her career??

AFAIK this term is use in two scenarios (along with rockstar developer, and guru):

- The company is proud of it's employee and describes them as such.

- The company is using the term in job ads, looking for experts who are willing to work for underpaid wages

@ananaszjoe I was gonna say the same thing (point #2) because that's the only time I've seen the term used tbh.

@sergiolarosa89 seems to same here.

I have read one from here,

https://javascript.info/ninja-code

and really it felt cool while reading it.

but later searched on internet about ninja coding then found some positive and negative feedback about it.

"What's ninja coding actually??"

Nothing. It's a stupid meaningless buzzword marketing term. Just forget about it whenever you see it.