Operations
Model routing
Choosing which model handles a request at run time, usually by difficulty, cost or availability.
Rather than hardcoding one model, routing treats model choice as configuration. Straightforward requests go to a fast cheap model; hard ones escalate.
Routing also provides fallback. Providers have outages, deprecate models and change prices. A system with ordered fallbacks degrades instead of failing, and switching primary provider becomes a config change rather than a rewrite.
For a business the benefit is plain: no single vendor can hold your product hostage.