The single biggest mistake I see tech leaders make is to assess the value of individual team members by the number of tickets they close.

That mistake is the root cause of the number one challenge faced by developers: Unrealistic expectations. When you focus on an individual’s count of closed job tickets, you ignore the wider context of the project work and normal team dynamics, and the results can be disastrous: Poor morale, poor developer retention, and slowed productivity.

– Eric Elliott in The Essential Guide to Building Balanced Development Teams, a great article recommended to me by a superb senior developer