Basic Interview Questions

What is Generative AI, and how is it different from traditional ML?

Traditional ML mostly predicts or classifies (spam or not, price of a house) from structured features, and usually needs a model trained for each task. Generative AI creates new content (text, code, images, audio) and large pre-trained models can do many tasks from a prompt alone, without task-specific training.

Traditional MLGenerative AI
one model per task, trained on labelled dataone foundation model, many tasks via prompts
output: a label or numberoutput: text, code, images
example: fraud score on a transactionexample: drafting the reply to a fraud complaint

What is a Large Language Model (LLM)?

An LLM is a neural network (a decoder-only transformer) with billions of parameters, pre-trained on a huge amount of text to predict the next token. Then it is fine-tuned to follow instructions and tuned with human or AI feedback (RLHF and similar) to be helpful and safe. Examples: Claude, GPT, Gemini, Llama, Mistral.

What does an AI engineer / GenAI developer actually do?

  • Builds products on top of LLM APIs or open models: chatbots, RAG systems, agents, extraction pipelines.
  • Writes prompts, tool definitions and retrieval pipelines; chooses models by quality, cost and latency.
  • Builds eval sets and measures quality; adds guardrails, caching, monitoring.
  • Usually does not train foundation models; that is ML research and ML engineering work.

What is the difference between open-weight and closed models?

Closed (API)Open-weight
ExamplesClaude, GPT, GeminiLlama, Mistral, Qwen, Gemma
AccessHTTP API, pay per tokendownload weights, run yourself (Ollama, vLLM)
Prostop quality, no GPUs to manage, fast to startdata stays on your servers, fine-tunable, fixed infra cost
Consdata leaves your network, vendor dependencyyou run GPUs, scaling, updates; usually lower quality per size