Comment Re:So far so good. (Score 1) 211
The structures are fine, it's just that turnover at the higher level is low.
There are usually as many manager as lead level developers in IT (at least there should be, where lead is the technical equivalent of director). The leads manage specific development activities (and should not be micro-managed). And if the manager/director and the lead(s) are competent (or in with upper management, or good at manipulation, I've seen it all), no one else can move up.
So, the senior developers will probably leave, after a few years, to seek increased salary or a lead position elsewhere.
In order to retain knowledge (this is very, very important), the leads should be carefully selected and compensated well. Then, turnover at the junior and senior level isn't that painful. Promote internal staff to leads, they will have the institutional knowledge that needs to be retained.