Compatibility Bridge Design

Design compatibility layers to bridge old and new systems during migration.

Migration Checklist

Adapter Design

• Define adapter interfaces for changed APIs
• Implement wrappers that translate old calls to new APIs
• Ensure adapters handle edge cases from both versions
• Verify adapter performance overhead is acceptable

Abstraction Layers

• Create version-agnostic abstractions over divergent APIs
• Isolate version-specific code behind clean interfaces
• Ensure abstractions do not leak implementation details
• Validate abstraction coverage for all affected call sites

Incremental Migration Path

• Define phase-by-phase migration milestones
• Ensure each phase produces a working system
• Identify safe stopping points for partial migration
• Provide rollback capability at each migration phase

Coexistence Strategy

• Verify old and new code can run side by side
• Check for shared state conflicts between versions
• Ensure dependency versions do not clash at runtime
• Validate integration tests cover coexistence scenarios

Output Format

Report findings with risk ratings:

Risk	Description
Critical	No viable compatibility path, redesign required
High	Complex bridging needed, significant effort required
Medium	Standard adapter pattern sufficient, moderate effort
Low	Minor shim needed, straightforward implementation