Clyde: Spent 6 months writing a custom CMS in Perl in support of Project X.
Bob: Spent 2 months writing a custom CMS in Rails to support Project X. 4 months writing feature A and B for Cool Project X while continuing to support the CMS.
Alice: Spent 6 months writing feature A, B, C and D for Project X.
If I was looking for a developer for Project Y, who looks better?