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AI Engineering Interview Questions

Nail interviews on LLMs, Prompt Engineering, Retrieval-Augmented Generation (RAG), and Vector Databases.

Written by:TechIdea AI Lab (AI Solutions Architect)
Reviewer:Interview Board
Last Verified:2026-06-25
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Editorial Integrity

Based on real AI engineering interviews from OpenAI, Anthropic, and leading AI startups.

BeginnerScenario Based

What is Retrieval-Augmented Generation (RAG) and why do we use it?

RAG is a technique where you search your own database for relevant facts, and then feed those facts to an AI model (like GPT-4) so it can answer a question accurately without hallucinating.

Deep Dive Explanation

Large Language Models (LLMs) are trained on public data up to a certain cutoff date. They don't know your private company data, and they tend to hallucinate when they don't know an answer. RAG solves this by intercepting the user's question, searching a Vector Database (like Pinecone) for relevant internal documents, and then sending both the question AND the relevant documents to the LLM. The LLM acts purely as a synthesizer.

Enterprise Use Case: If an employee asks an internal HR bot, 'What is the maternal leave policy?', a standard LLM might guess based on general US law. A RAG system will search the company's internal HR PDF, pull out the exact paragraph on maternal leave, give it to the LLM, and the LLM will reply: 'According to our 2026 handbook, you get 16 weeks of paid leave.'
💡 Interview Strategy:Emphasize that RAG solves the 'hallucination' problem and the 'private data' problem simultaneously. It's the standard for enterprise AI apps.
🚨 Common Pitfalls to Avoid:

Confusing RAG with 'Fine-tuning'. Fine-tuning changes the model's behavior and tone; RAG gives the model new facts.

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