Especially in high availability/load systems like Netflix IMO you need to reduce complexity and that means less modules that depend on 69 other modules, each of which depends on 69 modules etc.. What's going on as this sw proliferates is insane.

Then, you've got to be intimately familiar with every piece. There's no excuse when the source is readily available. I give these guys credit though they seem to take responsibility instead of just saying "express sucks". Some of their design choices seemed a little shaky.