Separation of duty for developers

Separation of duty is something that is, most likely, on top of mind for everyone of us. With most things, developers seem to be an exception for this.

Our development team is somewhat of a blind spot in our environment. We are planning, together with our DevSecOps team on implementing a separation of duty for our developers as well. But I find it difficult to define where that separation should be. On the IDE level? On the GitHub level? Or none at all?

Curious to hear your thoughts, implementation and/or challenges around this topic.