Model upgrades won't replace code maps

An author who built the open-source tool Sense argues that structural code maps provide deterministic, repo-specific facts that LLM-based coding agents cannot replace. A benchmark across 13 Ruby/Rails repositories shows state-of-the-art models (e.g., Claude Code with Opus 4.8 and GPT-5.5) miss many non-obvious dependents when operating 'cold' but perform substantially better when the agent is given a computed dependency map. The author reports consistent gains across multiple model families, demonstrates concrete failure modes where models produce confidently wrong or incomplete audits, and outlines three enduring advantages of maps: they are repo-specific, always current, and model-agnostic. The Sense project, its benchmark harness and raw data are public on GitHub, and the post includes instructions for running the scan locally to compare agent-only vs mapped results.