Towards Data Science

The Hidden Cost of LLM Routing: Why Switching Models Costs More

The article examines the practice of routing requests to different large language models (LLMs) during a single session. It reports that switching models mid‑session can negate the expected cost savings from using cheaper inference options. The author conducted tests to illustrate how these switches impact overall expenses.

Towards Data Science
Oct 15

Jev Your Engines: Seven Open Decision Models vs. a Generative LLM

The article compares seven open decision models with a generative large language model (LLM) in a hands‑on repository called Jev. It evaluates each model based on routing accuracy, latency, and output reliability. The comparison provides practical insights into how these models perform in real‑world scenarios.

By Lambert Leong
arXiv Computation and Language
Aug 25

Most of the LLM routing gap is task type

The paper investigates why large‑language‑model (LLM) routers—systems that select the best model for each query—often fail to outperform a single best model. By evaluating 14 models on 294 questions across seven task types and three languages, the authors find that a simple static mapping of task type to model improves 21 of the 29 questions that routing could potentially solve, and that learned routers do not significantly exceed this performance. The study highlights that most routing gains stem from task‑type specialization rather than complex learned decision rules.

By Janghoon Lee
Towards Data Science
May 29

RAG Is Burning Money — I Built a Cost Control Layer to Fix It

Most RAG systems are optimized for answer quality, not cost—and that blind spot gets expensive fast. In this article, I break down a production-ready cost control layer combining semantic caching, query routing, token budgeting, and circuit breaking, achieving an 85% reduction in LLM costs without sacrificing answer quality.

By Emmimal P Alexander