{"type":"post","id":"what-is-eval-driven-development-how-to-improve-52927d","slug":"what-is-eval-driven-development-how-to-improve-52927d","title":"What Is Eval-Driven Development? How to Improve AI Agents","description":"LangChain’s guide presents eval-driven development (EDD) as a three-step loop for improving agents: define the behavior, write an evaluation before building, and compare each change against a baseline.","retrieval_nugget":"LangChain’s guide presents eval-driven development (EDD) as a three-step loop for improving agents: define the behavior, write an evaluation before building, and compare each change against a baseline. The practical point for builders is that agent changes must be tested for regressions as well as gains.","published_at":"2026-11-09","updated_at":"2026-11-09","record_date":"2026-11-09","date_kind":"published_at","topics":["evals","agents","agent-loops"],"entities":["LangChain","LangSmith","Harbor","Terminal-Bench"],"related_patterns":["ai-native-orgs-move-to-review-and-orchestration"],"novelty_label":"new_angle","what_changed":"It frames evaluation as a continuous development loop for AI agents, including defining success criteria, comparing iterations, and feeding CI and production failures back into eval datasets.","prior_refs":[],"source_url":"https://www.langchain.com/blog/what-is-eval-driven-development","source_urls":["https://www.langchain.com/blog/what-is-eval-driven-development"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:what-is-eval-driven-development-how-to-improve-52927d","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/what-is-eval-driven-development-how-to-improve-52927d/","markdown":"https://newruntime.com/posts/what-is-eval-driven-development-how-to-improve-52927d.md","json":"https://newruntime.com/posts/what-is-eval-driven-development-how-to-improve-52927d.json"},"markdown_url":"https://newruntime.com/posts/what-is-eval-driven-development-how-to-improve-52927d.md","next_reads":[{"type":"topic","path":"/topics/evals/","url":"https://newruntime.com/topics/evals/","title":"Evals","reason":"Explore the evals topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/evals.md","json_url":"https://newruntime.com/topics/evals.json"},{"type":"topic","path":"/topics/agents/","url":"https://newruntime.com/topics/agents/","title":"Agents","reason":"Explore the agents topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/agents.md","json_url":"https://newruntime.com/topics/agents.json"},{"type":"topic","path":"/topics/agent-loops/","url":"https://newruntime.com/topics/agent-loops/","title":"Agent Loops","reason":"Explore the agent-loops topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/agent-loops.md","json_url":"https://newruntime.com/topics/agent-loops.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/sources/","url":"https://newruntime.com/sources/","title":"Sources","reason":"See the original sources this archive cites.","media_type":"text/html"}]}