Do not let one model provider become a single point of failure
Prices, limits, and quality all move. Routing and fallbacks are not trend-chasing; they are how an important workflow still has a way through.
A gateway should provide common authentication, observability, and failover boundaries without pretending that every provider has identical semantics.
Define an internal task interface
Let applications submit task type, data class, latency target, and budget; let routing choose the model. Avoid provider model names in UI code and preserve provider-specific capabilities when needed.
Fail over only replaceable failures
Fail over on rate limits, transient network errors, and regional outages. Do not reroute safety refusals, invalid inputs, or business validation failures. Account for context, tools, and structured-output differences.
Make routing rules testable
Log the rule, reason, selected model, latency, cost, and quality. Start with shadow traffic, then a small rollout, and retain a fast pin to a known model version.
Pre-release checks
- Sensitive data stays in approved regions
- Failover cannot duplicate side effects
- Routing changes are replayable and reversible
Sources
Related
Writing, extraction, long reasoning, and high-volume support do not need the same model. Cost, latency, privacy, and reliability rarely point to one name.
GPUs, operations, inference tuning, and downtime all land on the same ledger. Self-hosting only makes sense after you have done the math on volume and people.