What's the main difference between a 'prompt engineer' and an 'agent engineer'?
A prompt engineer focuses on crafting instructions for models; an agent engineer designs and coordinates systems (models, tools, databases, APIs) so agents perform real-world actions reliably and safely.
Why is system design the first essential skill for building agents?
Agents are orchestras of components—LLMs, tools, state stores, subagents—and require architecture to manage data flow, failures, and coordination, which is core backend/system design work.
What is a tool 'contract' and why does it matter?
A tool contract precisely defines expected inputs and outputs (types, patterns, required fields). Clear contracts prevent the agent from guessing or passing invalid data, crucial for sensitive actions like transactions.
How does retrieval engineering affect agent performance?
Retrieval (RAG) supplies contextual documents to models; poor chunking, embeddings, or ranking leads to irrelevant context and confident-but-wrong outputs, so retrieval quality caps agent accuracy.
Which reliability practices should agents implement to avoid production failures?
Implement retry logic with backoff, timeouts to avoid hangs, fallback paths for degraded modes, and circuit breakers to prevent cascading failures when external services fail.
What security threats are highlighted for agents, and how should teams mitigate them?
Prompt injection and other manipulations target agents as attack surfaces. Mitigations include strict input validation, output filtering, permission boundaries, and defense-in-depth for tool calls.