Always forward-looking. Never negative about current employer.
Answer:
"I am happy at the RHS and I have learned a lot there, but I feel I have reached the ceiling of what the environment can offer. The team is small, the infrastructure is medium-scale, and the pace of change is slower than I want. I want to be somewhere using Kubernetes, automation, and cloud infrastructure every single day at a larger scale, with a team that pushes me to grow."
If they push further:
"It is more about pace and scale than anything specific being wrong. I want a role where the technical challenge is consistent every day, not in bursts."