DHH in Years of irrelevance:
Programming platform experience is like knowing your way around the kitchen. Where are the knives, what size plates do we have, and what spices are available. It's very useful for getting things done without having to search high and low for every little thing. But it's also an asset with a cut-off point of diminished returns. Once you have a reasonably good idea where things are, it's no longer the bottleneck in your culinary performance.
Like chefs, like programmers. Peopleware quotes a study that six months seemed to be the cut-off point for programmers. Once they had six months under their belt, the platform knowledge was no longer the bottleneck in their abilities.
That sounds about right to me.
I have to agree. I also think that total years of experience in the software industry plays a huge part in an engineer's knowledge.
However, that's not always true either.
I interviewed a PhD this week that had an incredible amount of experience and knowledge, but all his platform knowledge was dated.
Years of Experience in Software + up-to-date platform knowledge = the world is your oyster.