I'm not sure why software would be any different. Bridges are complicated and made up of versatile submodules, just like software. Some other software engineer eventually designs the "bridge" and selects "beams" for the structure. If those beams fail to meet their specs, then the engineers who stood by them are at fault. If the bridge fails because the beams weren't used in accordance with their spec, or didn't have a spec at all, then the engineers who approved their use in the bridge is at fault.