Comment by astral303

Pouring foundation, installing plumbing and wiring the building is specialized by the physical necessity of these activities, which cannot be repeated without mistake at a great cost. That justifies specialization. Unlike building a bridge, compiling software is essentially free. QA, release engineering and database design can and should be repeated and iterated on by software engineers, because it is a necessary part of the development and removing it from the expected work distorts incentives.