Single Model vs. Model Router: The Platform Choice

The single-model phase

One strong default model is simple to debug, explain, and budget. Early teams should usually start there because product behavior matters more than perfect provider optimization.

When routing becomes useful

Routing helps when workloads separate cleanly: cheap summarization, high-reasoning planning, fast extraction, multimodal analysis, and fallback paths. The system needs observability or routing becomes guesswork.

The hidden cost

Every new route adds evaluation work. A router should track quality, latency, spend, provider errors, and user-visible regressions. Without that feedback loop, it can become complexity wearing an optimization costume.