Context engineering and prompt engineering solve related but very different problems. Prompt engineering focuses on how you phrase instructions to the model: tone, wording, examples, and formatting. Context engineering focuses on what information is provided to the model, when it is provided, and how long it stays there. Prompt engineering is a text-writing activity; context engineering is a systems-design activity.
Prompt engineering assumes the relevant information is already in the prompt. Context engineering assumes that deciding which information enters the prompt is the real challenge. For example, no amount of clever phrasing will help if the model sees outdated documents, contradictory instructions, or too much irrelevant text. Context engineering solves that by filtering, ranking, and pruning context before the model ever sees it.
In production systems, prompt engineering usually sits inside context engineering. You may have a well-crafted system prompt, but it is combined with retrieved context that comes from a retrieval layer backed by a vector database like Milvus or Zilliz Cloud. Prompt engineering shapes how the model interprets that context; context engineering ensures the context itself is correct, minimal, and relevant. Confusing the two often leads teams to endlessly tweak prompts when the real issue is unmanaged context.