Model routing is the single biggest cost lever in multi-agent setups. Half of an average coding session is exploration (grep, glob, read), which a small model handles fine. The writing and editing turns need a premium model. Routing each agent to the right model in YAML is two lines of config, the savings are typically 50-65% on real workloads.
Engineering notes from the Digitorn team. No marketing, no launch announcements, no "10 prompts that will change your life". Just the things we write that we'd want to read.