Model Routing, AI Gateways & Agentic Systems for Cost, Quality and Performance

Sending 100% of your production traffic to a single monolithic frontier model (such as GPT-4o, Claude 3.5 Sonnet, or Gemini 1.5 Pro) is the fastest way to burn 70% to 85% of your AI budget on low-entropy queries. Conversely, downgrading your entire fleet to an 8B open-weight model causes enterprise churn, customer escalations, and silent accuracy collapse on high-difficulty edge cases.

The industry has reached a decisive turning point: Model Routing is not a simple cost-cutting trick; it is an intelligent, multi-dimensional allocation function.

Model Routing, AI Gateways & Agentic Systems for Cost, Quality and Performance provides the definitive, mathematically rigorous system-design manual for senior, staff, and principal AI engineers. Spanning 15 comprehensive chapters, 75 fully worked senior system-design and production-incident interview scenarios, and 15 interactive, runnable production laboratories (model-routing-labs), this book transforms model selection from ad-hoc prompting heuristics into verifiable, observable, and resilient software engineering contracts.

Every architectural pattern in the manuscript is accompanied by production code in the companion repository (model-routing-labs), featuring a Next.js 14 dashboard and an asynchronous FastAPI routing engine equipped with deterministic simulation, Ollama local model support, and zero vendor lock-in.