Retrieval & knowledge systems
Build a grounded RAG application with citations
Retrieve → rerank → generate grounded answers with citations over a private corpus.
~20 focused hours·intermediate
Tools: LangChain/LlamaIndex, Vector DB (pgvector/Chroma), Reranker (cross-encoder or hosted rerank API), Citation formatting, Claude/GPT for generation
Market relevance — share of job ads asking for this
What employers mean
You should be able to…
- Build a retrieve → rerank → generate pipeline that answers questions grounded in a private corpus
- Return citations/source references alongside generated answers
- Handle 'I don't know' gracefully when the corpus doesn't contain an answer, instead of hallucinating
- Tune retrieval (top-k, chunk size, reranking) to improve answer quality
- Support multi-turn Q&A where follow-up questions still retrieve correctly
- Add a reranking step to improve precision after initial vector retrieval
- Deploy the RAG system behind an API or simple UI for others to query
Needs first: Generate embeddings and run vector search, Design and version prompts systematically
Learn — free, link-checked
The few resources that matter
Course · intermediate · 90 min · deeplearning.ai
LangChain: Chat with Your Data
End-to-end walkthrough from document loading to a working conversational retrieval chain. — DeepLearning.AI (Harrison Chase, Andrew Ng)
Build from · intermediate · 90 min · github.com
Anthropic Cookbook
Official recipes including contextual retrieval and RAG evaluation patterns tuned specifically for Claude. — Anthropic
Build from · intermediate · 120 min · github.com
RAG From Scratch
Builds every RAG stage (query translation, routing, retrieval, generation) from first principles instead of one black-box chain. — LangChain (langchain-ai)
Read · advanced · 40 min · huggingface.co
Advanced RAG on Hugging Face Documentation using LangChain
Covers reranking and query optimization plus a worked evaluation section, bridging pipeline-building and eval in one place. — Hugging Face
Course · advanced · 90 min · deeplearning.ai
Building and Evaluating Advanced RAG Applications
Pairs advanced retrieval techniques (sentence-window, auto-merging) directly with the eval metrics used to justify them. — DeepLearning.AI (Jerry Liu, Andrew Ng)
Practice
Grounded RAG assistant over Indian HR policy documents
Build a RAG assistant over a corpus of a company's HR policy PDFs or public Indian labour law documents, answering employee questions like 'how many casual leaves am I entitled to?' with cited sources. Implement retrieve → rerank → generate, and make the assistant explicitly refuse to answer when the corpus doesn't cover the question.
Done when
- Answers include inline citations pointing to the specific source document and section/page
- A reranking step measurably improves top-result relevance over vector-only retrieval, shown with before/after examples
- At least 5 out-of-corpus questions are correctly answered with 'not covered' instead of a hallucinated answer
- A simple API or UI lets a user ask multi-turn follow-up questions that retrieve correctly
Prove it
Evidence a recruiter can check
- Public GitHub repo with README showing architecture (retrieve→rerank→generate) and example Q&A with citations
- A before/after example showing reranking improving retrieved chunk relevance
- At least one documented case of the system correctly refusing an out-of-corpus question
- A short demo video or hosted link a recruiter can query
- Eval numbers, even informal (e.g. 8/10 correct-with-citation on a hand-labeled test set)
Interview
Questions you'll get asked
- Walk me through the architecture of a RAG pipeline you've built, retrieval to generation.
- How do you get an LLM to say 'I don't know' instead of hallucinating when the answer isn't in the retrieved context?
- What's the role of a reranker in a RAG pipeline, and when is it worth the added latency?
- How do you generate accurate citations that point back to the exact source chunk?
- How would you handle a follow-up question in a multi-turn RAG conversation where the retrieval query needs the prior turn's context?
- How do you decide top-k for retrieval, and what happens if it's too low or too high?
- How would you extend a RAG system to work well over a mix of English and Hindi documents?