Close is hiring a Senior Backend Engineer (USA only, 100% remote) to work on the Agents team responsible for the agent core, eval/observability, MCP surface, and orchestration for voice/chat/custom agents. The role centers on Python backend engineering, production LLM/agent features, evals and tracing, event-driven/custom agent work, and integrating deterministic workflows with non-deterministic LLM outputs. Tech touched includes Python/Flask, Temporal, LangFuse, PostgreSQL, MongoDB, Elasticsearch, Redis, AWS, Docker, and Kubernetes.