Introduction to LangChain: Concepts, Models & LLM Integration

A comprehensive introduction to LangChain explaining its core concepts, supported model types, and hands-on integration with Ollama LLMs, chat models, and embedding models.

December 29, 2025 · 3 min · 561 words · Nirajan Khatiwada

Prompt Engineering in LangChain: Templates, Messages & ChatPromptTemplate

Learn how to control and structure prompts in LangChain using PromptTemplate, message classes, and ChatPromptTemplate to build safe, consistent, and context-aware chat applications.

December 29, 2025 · 6 min · 1084 words · Nirajan Khatiwada

Structured Output in LangChain: Pydantic Models & Output Parsers

Learn how to enforce structured outputs in LangChain using Pydantic schemas, with_structured_output, and output parsers to build reliable, production-ready LLM applications.

December 29, 2025 · 5 min · 942 words · Nirajan Khatiwada

Chains in LangChain: Sequential, Parallel & Conditional Workflows

Learn how to compose powerful LLM workflows in LangChain using chains, including sequential, parallel, and conditional execution patterns with real-world examples.

December 29, 2025 · 4 min · 788 words · Nirajan Khatiwada

Runnables in LangChain: Building Modular & Composable LLM Workflows

Learn how LangChain Runnables work and how to compose flexible, reusable, and scalable LLM workflows using sequences, parallel execution, branching logic, and LCEL syntax.

December 29, 2025 · 5 min · 1060 words · Nirajan Khatiwada

RAG in LangChain: Introduction and Loaders

Learn how RAG combines retrieval-based and generative models to create accurate, up-to-date, and scalable LLM workflows using LangChain’s document loaders, retrievers, and vector stores.

January 23, 2026 · 4 min · 726 words · Nirajan Khatiwada

Text Splitters in LangChain: Efficiently Chunking Large Documents for LLMs

Learn how to split large texts into manageable chunks for LLMs using various splitting strategies, improving embeddings, retrieval, and summarization tasks with LangChain’s Text Splitters.

January 23, 2026 · 5 min · 1034 words · Nirajan Khatiwada

Vector Stores in LangChain: Embeddings, Semantic Search & Similarity Retrieval

Learn how vector stores work in LangChain, from embeddings and similarity search to using Chroma for storing, querying, filtering, and managing high-dimensional vector data in RAG and recommendation systems.

January 23, 2026 · 6 min · 1082 words · Nirajan Khatiwada

Retrievers in LangChain: Data Sources, MMR & Contextual Compression

Understand how retrievers work in LangChain, explore different retriever types, and learn how to use MMR and Contextual Compression to improve relevance, diversity, and efficiency in RAG pipelines.

January 23, 2026 · 6 min · 1093 words · Nirajan Khatiwada

Retrieval Augmented Generation (RAG) in LangChain: Architecture & Practical Example

Learn how Retrieval Augmented Generation (RAG) works in LangChain with clear architecture diagrams and a complete YouTube summarizer chatbot implementation using Chroma, Ollama, and runnable chains.

January 26, 2026 · 5 min · 910 words · Nirajan Khatiwada