Renovate Bot

Renovate is the most impactful tool on this list relative to its complexity and the least likely to be on any other DevOps list. It's a dependency update bot — you install it in your GitHub/GitLab org, and it automatically opens PRs to update package.json, requirements.txt, Dockerfiles, Helm chart versions, and Terraform provider versions. The reason it's here: the #1 source of critical CVEs in production systems is not sophisticated attackers exploiting zero-days — it's known vulnerabilities in outdated dependencies that weren't updated because updating was tedious. Renovate eliminates the tedium. With auto-merge rules configured for patch versions and test suite gates, a properly configured Renovate setup keeps hundreds of dependencies current with near-zero human effort.