[_jal]

Past the proof of concept, "developers" should frankly not be making these decisions. People who understand systems and failure analysis should be. You might have devs with that experience, but they're comparatively rare.

As far as complexity... if you get big enough, you can't avoid it. My meta-rule is to only accept additional complexity if solving the issue some other way is impractical.

It is almost always far, far easier to add additional moving parts to your production environment than it is to remove them after they're in use.