Online writer, second-rate feller (7)
I believe the answer is:
blogger
'online writer' is the definition.
'blogger' can be an answer for 'writer' (I have seen 'Modern writer' mean 'blogger' so perhaps 'writer' could also mean 'blogger'). I am not certain of the 'online' bit.
'second-rate feller' is the wordplay.
I cannot quite see how this works, but
'second' could be 'b' (B can mean second eg B-side) and 'b' is present in the answer.
The remaining letters 'logger' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for blogger that I've seen before include "like Guido Fawkes?" , "Internet recording artist" , "Journal-writer on the internet" , "One keeps a web log" , "Contemporary diarist" .)