I am a software engineer, still at my first job in the software development field. Talking to a friend got me wondering if there is a point where I'll be hurting my career by staying put (in terms of hireability by future potential employers).
If I stay here until I have ten or fifteen years experience, then yes, that's ten or fifteen years of experience; but is the impact diluted by the fact that it's all at one place? I could imagine a hiring manager seeing such a resume and thinking "Sure, he's stable; but this only proves that he can do the SAME job for a long period. What'll happen when he's exposed to something different? New technologies? Different challenges? Even a different corporate culture might make him a completely different employee than he's been at XYZ Company."
My question is not about whether those concerns are valid or how to address them if I find myself in that position. Rather, my question is about making sure I don't get there in the first place: how long can I stay at my first software job before the duration has probably started to become a liability in the eyes of prospective employers? (Or, does such a point in time even exist in the first place? Or am I worrying about nothing?)
To put it a different way: what will make me a more hireable candidate when I'm 15 years into my career? Having all 15 at one place or having 5 at three different places? Perhaps the 15 would be more palatable if there was evidence of significant upward movement in that time, but my question is about whether the duration itself is detrimental, holding all other factors equal.