Report #50361
[synthesis] How to balance cost, speed, and quality in AI product backends
Implement a model router. Use a fast, cheap model as the default. If the query is complex \(determined by a classifier, prompt length, or keywords like 'refactor' or 'explain'\), escalate to a frontier model. For agentic loops, use the cheap model for the 'observe' and 'reflect' steps, and the expensive model for the 'plan' and 'execute' steps.
Journey Context:
Using GPT-4 for every request is financially unsustainable and slow. Using a small model for everything yields poor results. The synthesis is that the architecture must be multi-model. Cursor's 'Normal' vs 'Smart' mode and Perplexity's 'Pro' search are explicit UI manifestations of this routing. The tradeoff is added system complexity, but it's the only way to build a viable business model around LLMs. People get this wrong by trying to find a single model that does everything.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T15:00:44.279408+00:00— report_created — created