shared-lib/
├── src/
│   ├── auth/
│   │   ├── JwtValidator.ts
│   │   └── PermissionChecker.ts
│   ├── logging/
│   │   └── Logger.ts
│   ├── email/
│   │   └── EmailSender.ts
│   └── payment/
│       └── StripeClient.ts
└── package.json  // version 1.2.3

# Version 1.2.4 fixes JWT bug
# But users of EmailSender must also upgrade
# Changelog unclear which features affect which users

packages/
├── auth/
│   ├── src/
│   │   ├── JwtValidator.ts
│   │   ├── PermissionChecker.ts
│   │   └── index.ts
│   ├── CHANGELOG.md        # Auth-specific changes
│   └── package.json        # @company/auth v2.1.0
├── logging/
│   ├── src/
│   │   └── Logger.ts
│   ├── CHANGELOG.md
│   └── package.json        # @company/logging v1.0.3
├── email/
│   ├── src/
│   │   └── EmailSender.ts
│   ├── CHANGELOG.md
│   └── package.json        # @company/email v1.5.0
└── payments/
    ├── src/
    │   └── StripeClient.ts
    ├── CHANGELOG.md
    └── package.json        # @company/payments v3.0.0

# Clear ownership: auth team owns @company/auth
# Independent versioning: JWT fix only bumps auth
# Semantic versioning: breaking change in payments doesn't affect others