Replacing a core system takes years. Meanwhile, the business needs new channels and features. A clean API layer separates what consumers need from how the old system works.
Benefits
- New applications and AI agents use one controlled interface instead of reaching into legacy internals.
- Access rules, logging and rate limits live in one place.
- The back end can later be replaced without changing the consumers.
Cautions
- Don't expose raw legacy structures; design the interface around business operations.
- Plan for the old system's speed and downtime windows.
- Version the API and document it.
Done well, the wrapper becomes the seam along which the replacement is later introduced.