Never tried coderabbit, just because this is already good enough with Claude Code. It helped us to catch dozens of important issues we wouldn't have caught. We gave some instructions in the CLAUDE.md doc in the repository - with including a nice personalized roast of the engineer that did the review in the intro and conclusion to make it fun! :) Basically, when you do a "create PR" from your Claude Code, it will help you getting your Linear ticket (or creating one if missing), ask you some important questions (like: what tests have you done?), create the PR on Github, request the reviewers, and post a "Auto Review" message with your credentials. It's not an actual review per se but this is enough for our small team.