This role spans three connected areas: Infra that users feel — own our core systems (PostgreSQL, ClickHouse, async job processing, LLM gateway, email infra) with the same product instincts an engineer would bring to a customer-facing feature. Own, operate, and evolve our core data infrastructure: PostgreSQL, ClickHouse, and async processing pipelines — measuring success in user-facing terms (p95 scheduling latency, agent action success rate, message delivery reliability).