Skip to main content

Topic Hub

LLM Engineering

LLM Engineering is the discipline of shipping production systems built on large language models — covering RAG architecture, fine-tuning strategies, model evaluation, and the practical tradeoffs that determine what gets deployed versus what stays in a notebook. These articles cover the technical decisions that matter when you move from prototype to production.

RAG Fine-Tuning LLM Architecture OpenAI Production AI

Articles 14

Frequently Asked Questions

What is LLM Engineering?

LLM Engineering is the practice of building production systems with large language models. It covers model selection, prompt design, RAG architecture, fine-tuning strategies, evaluation pipelines, and inference optimization — the full technical stack between a raw model and a working AI product.

What is the difference between RAG and fine-tuning for LLMs?

RAG (Retrieval-Augmented Generation) fetches relevant context at inference time from an external knowledge base, making it ideal for dynamic or frequently-updated information. Fine-tuning adjusts model weights for specific tasks or communication styles and is better for consistent behavior and lower-latency responses. Most production systems combine both: fine-tuning for style and RAG for knowledge.

How have GPT-5 models changed production LLM engineering?

GPT-5.3 introduced significantly fewer refusals and better instruction following, reducing prompt engineering overhead. GPT-5.4 added expanded context windows and improved agentic tool use, making it easier to build reliable multi-step pipelines without complex fallback logic.

When should I consider running LLMs locally?

Local LLMs make sense for private codebases, high-volume batch tasks where API costs add up, offline workflows, and experimentation without usage limits. Models like Qwen3-Coder are viable for coding assistance on modern hardware. The tradeoff is quality: frontier models still outperform local alternatives on complex reasoning tasks.