LangChain Tutorial

1. LangChain Introduction

What LangChain is, the problem it solves, and how to install it.

2. Chains & Prompt Templates

Prompt templates, a simple prompt-model-parser chain, and why chaining steps together is useful.

3. Memory & Conversational Chains

Buffer, window, summary and token-limited memory patterns, and a complete conversational chain example.

4. Agents & Tools

What a LangChain agent is, tool selection with a calculator and search example, and the think-act-observe loop.

5. Retrieval Chains & RAG Integration

Wiring a vector store into a LangChain retriever and composing a full retrieval-augmented generation chain.

6. Production Patterns & Error Handling

Retries with backoff, timeouts, streaming responses, and controlling LLM API cost in a real application.

7. Observability & Debugging

Tracing chain execution step by step, and the common failure modes that only show up when you look inside a chain.

8. LangChain Interview Questions

Commonly asked LangChain interview questions with clear, practical answers.