From weeks to a day: how we made LLM evaluation fast enough to iterate on

AirbnbJun 4, 2026

Sitar-agent: Building a reliable dynamic configuration sidecar at scale

Here is a concise summary of the blog post in 3 sentences: Airbnb engineers built Sitar-agent, a lightweight Kubernetes sidecar that delivers dynamic configuration reliably at scale. The sidecar runs alongside every subscribed service pod, synchronizing the latest configurations from the service backend and making them available on the local filesystem for reads. Through key design decisions, including a snapshot-based S3 preload and a pull model with server-side optimization, the Sitar-agent sidecar achieves reliability, performance, scalability, and multi-language support despite the constraints of delivering dynamic configuration at Airbnb's scale.

FrontendData Science

11 min

From weeks to a day: how we made LLM evaluation fast enough to iterate on

Scaling beyond one: How Airbnb evolved its data architecture for a multi-product world

Sitar-agent: Building a reliable dynamic configuration sidecar at scale