LangGraph Agents

Course Content

LangGraph Agents

7 sections · 49 lessons

What are common real-world use cases where LangGraph works better than a linear pipeline?


What you need to know

For each use case, name the graph feature that makes it a good fit:

Use caseThe graph feature it needs
Support triage with escalationConditional routing, interrupt() for the human, resume
Agentic RAGCycle: grade → rewrite → retrieve, with a budget
Code / SQL agentCycle: run → read error → repair, capped
Document extractionConditional edge to re-extract only failed fields
Research assistantFan-out with Send, reducer, fan-in to synthesis
Refund or payout approvalDurable pause, checkpointer, idempotent side effect
Multi-session assistantthread_id checkpoints plus a long-term Store
Multi-step insurance claimSubgraphs per stage, days-long pauses, audit history

What makes a use case a poor fit

  • One prompt in, one answer out (summarise, translate, classify).
  • A fixed sequence with no failure branch.
  • High-volume, low-latency paths where every checkpoint write costs milliseconds you cannot spare.

A real-life example

A broadband provider's support bot remembers each customer across sessions. On Monday a customer says their router is a dual-band model and they prefer Hindi. The graph saves the transcript under thread_id="cust-4471-2026-09-21" with a Postgres checkpointer, and a remember node writes {"router": "dual-band", "language": "hi"} to a long-term Store under the namespace ("customers", "4471"). On Thursday, in a new conversation with a new thread, the bot reads the Store first, answers in Hindi and skips the "which router do you have?" question. The flow also branches: after two failed troubleshooting steps it books a technician visit, which needs a human dispatcher to confirm a slot — an interrupt() that may wait two hours. None of this fits a linear pipeline.

Follow-up questions to expect

  • "When would you not use LangGraph for an agent?" — When create_agent with middleware already covers it, or when the task is a single call. Less framework means fewer moving parts.
  • "How is short-term memory different from long-term memory here?" — Short-term is the thread's checkpointed state; long-term is a Store shared across threads, keyed by user.
  • "What is the latency cost?" — Mostly the checkpoint write per super-step. With the default durability="async" it overlaps the next step; use "exit" if you only need saving at the end.