LLM Engineer skills & stack

The skills and tools employers expect from a LLM Engineer, plus what each level is expected to own.

Core skills

Typical stack & tools

What you'll actually do

• •Build retrieval-augmented generation (RAG) systems: chunking, embeddings, retrieval
• •Fine-tune or adapt models and evaluate whether it beats prompting
• •Own inference and serving: latency, throughput, cost, caching
• •Build eval pipelines and quality gates for LLM features
• •Integrate LLMs into products via APIs, SDKs, and tool use

Skills by level

Junior

Builds LLM features against clear specs (RAG, prompts, integrations).

Mid

Owns an LLM system end-to-end: retrieval, serving, evals, cost.

Senior

Designs LLM infrastructure and standards; often grows into agent engineering.