Over time, you might outgrow the patterns and practices you use to collaborate on infrastructure as code. Even change techniques like blue-green deployment cannot solve conflicts in configuration or changes as your team works on some IaC. You must deliver a series of major changes to your IaC and address problems with scaling the practice.
For example, the sundew team for Datacenter for Carnivorous Plants expresses that it can no longer comfortably and confidently roll out new changes to its system. The team puts all infrastructure resources in one repository (as per the singleton pattern) to quickly deliver the system and just kept adding new updates on top of it.
The sundew team outlines a few problems with its system. First, the team finds its updates to infrastructure configuration constantly overlapping. One teammate works on updating servers, only to find another teammate has updated the network and will affect their changes.