JavaScript and TypeScript projects don't collapse from a single flaw—they architecturally drift from small, cumulative changes. A developer's simple import triggered 47 failing tests due to a hidden circular dependency. This decay happens while all tests pass and ESLint remains silent, creating a codebase that feels increasingly fragile and unchangeable over time.

Common symptoms include massive 'god modules,' layer violations where domain logic imports UI code, and shotgun surgery where one change touches dozens of files. The core issue is that architecture isn't treated as a versioned artifact. Without a baseline, every pull request risks introducing an invisible regression, making teams fearful of modifying their own code.

The solution is regression-based architecture. Teams can document their current module structure as a baseline and use CI tools like Archlint to compare new PRs against it. This flags new architectural violations automatically, forcing conscious decisions instead of accidental decay. The goal isn't perfect architecture, but preventing it from worsening unknowingly.