Being a generalist isn't always an easy sell, but we can be uniquely valuable in a small shop that lacks an army of specialists. Just since last year I've been called on to document several protocols for partners, design and back-test a Bayesian estimator, troubleshoot a balky load balancer using only a tcpdump (it was reusing port numbers too aggressively), sleaze together some last-minute map/reduce analytics feeding Excel graphs, and track down regressions caused by bad svn merges. Nobody sane would put all of that in one job description (nominally I maintain a soft realtime Java app server), yet someone had to do it, and there I was. As a specialist I'd worry about only getting asymptotically better at solving one problem which could become irrelevant.

Actually it's the stuff I'm supposed to know how to do where I feel like a fraud, because I compare the imaginary progress of an idealized version of myself to what I've actually accomplished. When I'm handling one of these tasks from left field, everyone knows I'm winging it, and that makes success sweeter.