The team behind HailBytes reNgine attempted to create hardened Ubuntu 24.04 images for AWS and Azure, following CIS benchmarks. Their security tools immediately broke because kernel hardening blocked BPF access, which packet scanners require. This created a core paradox: hardening removed the privileges their own tools needed.

They used Claude Code to debug three critical issues. First, their cloud detection script failed because Azure and AWS share the same metadata IP. The fix required validating response formats, not just connectivity. Second, Ubuntu 24.04 renamed the SSH service from `sshd` to `ssh`, breaking restart commands. Third, they documented specific trade-offs, like allowing BPF for scanning.

The resulting script hardens SSH, UFW, kernels, and Fail2Ban while keeping Docker and scanners functional. Key lessons include testing on actual targets, validating API responses, and documenting every deviation for auditors. This approach proves that security tooling requires careful balancing, not just blindly applying benchmarks.