So large companies should occasionally do a mark and sweep collection to account for bugs in the standard reference counting implementation. Particularly useful if the org chart allows cycles.
You know, GC isn't a bad metaphor for it. I imagine stack ranking might actually work if you approached it as a generational mark-sweep. Once a quarter, fire your bottom 10% of new employees. If an employee survives that, they move onto the next generation and skip a mark phase or three . The next time they get GC'd, they move onto the next generation and now only get it once every two or four years, etc. It would reduce overhead and false positives, and hopefully fix some of the bullshit political machinations that occur.
