Often times in academics we are anticipating a job change in the near future. Postdocs, in particular, since this is supposed to be a temporary job. But faculty occasionally anticipate a job change too. On the market b/c you fear tenure won't fall, to leverage progress into a better job, to jump out of the rat race, to join Administration.
I give advice based on Yoda's wisdom.
Yoda: Ready are you? What know you of ready? For eight hundred years have I trained Jedi. My own counsel will I keep on who is to be trained. A Jedi must have the deepest commitment, the most serious mind. This one a long time have I watched. All his life has he looked away... to the future, to the horizon. Never his mind on where he was. Hmm? What he was doing. Hmph. Adventure. Heh. Excitement. Heh. A Jedi craves not these things. You are reckless.
No, not the paternalistic grouch stuff. In this he is worse than a greybeard of science.
No it is the part about doing a good job on what you are currently doing. To me this is the basis for making the future stuff more likely to go your way.
No matter how removed the anticipated job category, the candidate who has been successful in her previous job is going to look better.
I entertained the McKinsey thing at one point during my training. Looked into it, saw who they hired and spoke to a friend of a sibling who went that way. They did not want people who had a disappointing career in science up to that point. They knew what CN or S publications meant. They wanted excellence.
Now of course plenty of people get alternative career jobs after a disappointing career as grad student or postdoc. But I think the take away message is that you should maximize your success in whatever job you are doing now. Don't just slack because you plan to be out-o-here in a year.
Success now increases the chances of getting into whatever next job lies over the horizon.
There is also the consideration that you may find yourself staying in the job you have much longer than anticipated or desired. A year from now, you don't want to look back and wish you had finished that experiment, paper, grant application or whatever.
Work based on the idea you may still be in this job in a year or three. Sometimes things happen. Maybe the local institution finally steps up and does you a solid. Maybe that firm job offer elsewhere is denied by the Dean or P&T committee. Maybe the University System puts down a hiring freeze.
You'll be better off if you are taking care of business in your existing job.