[Remote] Principal AI Engineer at Apollo.io

The Principal AI Engineer will lead the design and deployment of cutting-edge agentic systems, AI assistants, and LLM-powered features, owning the architecture and productionization of intelligent systems. This includes architecting and leading the development of autonomous AI agents capable of long-horizon planning, reasoning, and API orchestration, as well as building reusable agentic components for workflow automation. The role also involves owning and evolving the in-house platform for scalable LLM and agent deployments, leading the design of conversational AI and UI powered by NLU and RAG, and building semantic and personalized search systems. Additionally, the engineer will drive innovation in personalized outreach generation using context-aware generation pipelines and optimize inference pipelines, caching layers, and model selection logic for high-scale, cost-aware performance, while defining and driving robust evaluation methodologies and architecting human-in-the-loop systems.