Building production-grade deep research agents requires solving reliability and observability challenges that demos hide. This walkthrough shows how to combine Temporal's Durable Execution with Braintrust's tracing and evals to create a resilient multi-agent pipeline. The system uses four specialized agents (planning, query generation, web search, report synthesis) mapped to Temporal Activities, enabling automatic retries, parallel search with graceful degradation, and structured Pydantic data contracts between agents. Braintrust's plugin integrates directly with the Temporal Worker to capture full execution traces, enabling root-cause analysis across all agent stages. Production traces feed into evaluation datasets, creating a feedback loop for systematic prompt improvement rather than reactive firefighting.
