Still it is a faulty metric.
200% improvement may just be the result of feature A and 40% may just be the max performance gain from feature B. Comparing developers over the effectiveness of features they implement is mostly rating the PMs or the leadership they work with. Its a dice roll and its a measure of one's luck to be at the right place & right time to work on the right task.
>Its a dice roll and its a measure of one's luck to be at the right place & right time to work on the right task.
In general you pick companies, products, teams, initiatives, tasks that you're interested about, so it's not like it is purely dependent on luck
If you have skills and see opportunity then going for that may result in nice outcomes :)
Then what's your proposal?
People complain about using metrics. People complain about rating performance based on what your manager or coworkers say about you. Performance reviews are an unsolved hard problem.