Route tasks by failure mode, not brand name
Model routing is usually framed as cost or quality. The more useful frame is failure. Which model omits caveats, over-refuses, invents sources, follows schemas, or handles long contexts under pressure?
Build small route tests around the jobs you actually run. A model that wins general reasoning may still be the wrong choice for structured extraction if it casually fills unknown fields.
Keep routing reversible. When model behavior shifts, the route table should be an operational setting backed by evidence, not a belief system.
Aha moment
Routing by failure mode is more useful than routing by reputation because every model breaks differently.
Try this
Build a route table from observed task fixtures: extraction, synthesis, coding, refusal review, and long-context use.
Watch for
- Leaderboards used as a substitute for local fixtures
- Model routes that cannot be changed without code edits
- Ignoring behavior drift after model updates