# Track 11: LangChain & LangGraph

The framework layer for everything track 10 just built by hand.
LangChain first (models, prompts, parsers, LCEL, chains, memory, tools,
retrievers), then LangGraph — which replaces linear chains with an
explicit state graph supporting cycles, branching, checkpointing and
human-in-the-loop, and which track 12's multi-agent systems run on top
of.

## Modules

1. Why Frameworks Exist (and When to Skip Them)
2. LangChain Architecture Overview
3. Models and Messages
4. Prompt Templates
5. Output Parsers
6. LCEL: The LangChain Expression Language
7. Chains
8. Memory in LangChain
9. Tools and Toolkits
10. Retrievers and Vector Store Integration
11. LangChain Agents
12. Why LangGraph: The Limits of Chains
13. LangGraph: State and Nodes
14. LangGraph: Edges and Conditional Routing
15. LangGraph: Cycles and Loops
16. Checkpointing and Persistence
17. Human-in-the-Loop With LangGraph
18. LangSmith for Tracing and Debugging
19. Capstone Project