When a single feature calls several models, your throughput is bounded by the slowest, busiest upstream. A few patterns keep latency predictable under load.
Fan-out with backpressure
Cap concurrency per model rather than globally. A bounded queue in front of each upstream prevents one slow provider from starving the rest of your request budget.
Retries with jitter
Retry on 429 and 5xx with exponential backoff plus random jitter, so a burst of retries does not synchronise into a second spike. Always cap total attempts.
Graceful degradation
Decide ahead of time what 'good enough' looks like: fall back to a cheaper model, return a cached result, or degrade the feature rather than failing the whole request. Apifuse's multi-provider routing handles failover for you, but your app should still have an opinion.