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 case | The graph feature it needs |
|---|---|
| Support triage with escalation | Conditional routing, interrupt() for the human, resume |
| Agentic RAG | Cycle: grade → rewrite → retrieve, with a budget |
| Code / SQL agent | Cycle: run → read error → repair, capped |
| Document extraction | Conditional edge to re-extract only failed fields |
| Research assistant | Fan-out with Send, reducer, fan-in to synthesis |
| Refund or payout approval | Durable pause, checkpointer, idempotent side effect |
| Multi-session assistant | thread_id checkpoints plus a long-term Store |
| Multi-step insurance claim | Subgraphs 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_agentwith 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.