LangChain

Beginner — What does LangChain provide?

• Reusable model, prompt, tool, and retrieval components and higher-level agent integrations.
• It helps compose applications but does not own domain security or guarantee output truth.

Intermediate — What is a chain?

• A sequence of transformations or calls, such as prompt → model → parser.
• A chain can be deterministic and is not automatically an agent; an agent chooses some actions based on observations.

Senior — When would you avoid LangChain?

• For a small direct API call with clear validation, plain SDK code may be easier to understand and maintain.
• I adopt abstractions when they reduce actual integration complexity and keep provider requests, costs, and failures inspectable.

Scenario — A tutorial's imports fail. What do you do?

• I identify its intended version, consult the current official docs, and separate the concept from the old API.
• I pin compatible dependencies and avoid mixing legacy chain APIs with newer agent construction patterns.