LLM engineers and RAG engineers build different types of generative AI applications. Understanding their skills and focus areas helps you hire the right talent for your AI project.
Core responsibilities day to day
Technical expertise required
Where answers come from
Likelihood of generating false information
How quickly new information is available
Difficulty of building the system
Typical annual compensation
LLM engineers build general generative AI applications. RAG engineers specialize in question-answering over your documents. For most production applications with proprietary data, you need RAG expertise.
LLM engineers understand transformer architecture, prompt engineering, fine-tuning, and LLM APIs. They can build chatbots, code assistants, content generators, and general-purpose AI applications. Their expertise is model-centric: selecting the right model, optimizing prompts, fine-tuning for specific tasks, and managing inference costs. They may not deeply understand retrieval systems or evaluation for factual accuracy.
RAG engineers specialize in connecting LLMs to your data. They build document ingestion pipelines, vector databases, retrieval strategies, and evaluation frameworks. Their expertise is data-centric: chunking documents, embedding models, similarity search, re-ranking, and hallucination detection. They ensure LLMs answer accurately based on your specific documents.
Most production LLM applications today use RAG. Pure LLM engineering without retrieval is rare for enterprise use cases because models hallucinate and don't have access to your data. The best AI engineers understand both LLM and RAG techniques. However, specialists still exist, and you may need both depending on your application complexity.
Raise a request → Talk to experts → Fund the project → Expert works → Review & approve payment
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