I only just started using it at work in the last month.

I am a data engineer maintaining a big data Spark cluster as well as a dozen Postgres instances - all self hosted.

I must confess it has made me extremely productive if we measure in terms of writing code. I don't even do a lot of special AGENTS.md/CLAUDE.md shenanigans, I just prompt CC, work on a plan, and then manually review the changes as it implements it.

Needless to say this process only works well because: A) I understand my code base. B) I have a mental structure of how I want to implement it.

Hence it is easy to keep the model and me in sync about what's happening.

For other aspects of my job I occasionally run questions by GPT/Gemini as a brainstorming partner, but it seems a lot less reliable. I only use it as a sounding board. I does not seem to make me any more effective at my job than simply reading documents or browsing github issues/stack overflow myself.