Dynamic Subagents: How to Run Parallel Agents Reliably in Deep Agents

Colin Francis, a software engineer at LangChain, walks through dynamic subagents — a new feature in Deep Agents that lets your agent spawn and coordinate subagents programmatically by writing code. Instead of relying on the agent to orchestrate dozens of tool calls in sequence (and inevitably losing the plot), the orchestration logic moves into code, giving you reliable coverage at scale and real control flow. The video covers all six patterns — from Classify and Act to Loop Until Done — with live LangSmith traces for each. 0:00 What are dynamic sub-agents? 0:31 Live demo: 15 parallel subagents in Deep Agents 1:44 Why sub-agents alone aren't enough 2:52 The book-summarization example 3:35 Orchestration in code vs. in the agent's head 4:40 How the code interpreter middleware works 5:01 The task global: spawning subagents from code 5:48 How to trigger it with the workflow keyword 6:52 The six patterns overview 7:24 Pattern 1: Classify and Act 11:01 Pattern 2: Fan Out and Synthesize 13:37 Pattern 3: Adversarial Verification 17:27 Pattern 4: Generate and Filter 21:00 Pattern 5: Tournament 23:29 Pattern 6: Loop Until Done 25:23 Wrap-up and getting started Extra resources: Deep Agents: https://www.langchain.com/deep-agents