What a harness is. The engineering scaffolding around LLM calls that turns a demo into a product: retry logic, output parsing, error handling, configuration management, rate limiting, timeout...

Build a production-ready LLM call wrapper. Implement: retry with exponential backoff, timeout handling, structured output parsing (tool use or Pydantic), error classification (retryable vs....

"Walk me through how you'd build the infrastructure around LLM calls for a production application." Start with the call wrapper: Anthropic/OpenAI SDK with retry logic (exponential backoff, 3 retries...