Principal Engineer, Agentic AI Systems

About Inflection AI Inflection AI is a Public Benefit Corporation empowering people with human-centered, emotionally intelligent AI. We’re shaping the future of AI by combining emotional intelligence (EQ) and raw intelligence (IQ) to elevate people’s potential. Inflection AI created Pi, the world’s first emotionally intelligent AI, to help people work through decisions, emotions, and challenges. Pi is a personal AI agent powered by Inflection AI’s foundation model, proving that AI can be personal, empathetic, and contextually aware. About the Role We're looking for a hands-on Principal Engineer to lead the architecture and technical direction of Inflection's agentic AI systems. You'll build production AI agents that can reason, retrieve context, use tools, and safely execute complex workflows while driving the design of scalable agent architectures, evaluation frameworks, observability, and reliability systems. Partnering closely with product, design, and engineering, you'll turn ambiguous problems into AI-native experiences, mentor senior engineers, and help establish the technical standards that power the next generation of intelligent agents. What You’ll Do Build production AI agents that can plan, retrieve context, call tools, take actions, and recover from failures. Design agent architectures for task decomposition, tool routing, memory, state management, human approval, and safe execution. Create evals and observability systems for multi-step task success, tool-call accuracy, hallucination resistance, latency, cost, and failure modes. Integrate agents with APIs, databases, SaaS tools, enterprise systems, internal systems, and user-facing workflows. Improve reliability through structured outputs, guardrails, fallback paths, monitoring, permissions, auditability, and human-in-the-loop controls. Partner with product, design, and engineering teams to turn ambiguous user problems into shipped AI-native features. Make pragmatic model and infrastructure choices across proprietary models, open-source models, orchestration frameworks, vector databases, and cloud environments. Contribute to technical direction, engineering best practices, and the quality bar for agentic AI systems. Own the technical direction of agentic AI systems, provide support and coaching to the team. What We're Looking For 10+ years of engineering experience, including 3+ years at staff/principal or equivalent scope, and 2+ years building production-grade agentic or LLM-powered systems used by real customers. Strong Python or TypeScript experience. Experience building LLM-powered products, AI agents, RAG systems, automation workflows, or model-integrated applications. Strong backend engineering fundamentals, including APIs, databases, queues, testing, observability, cloud infrastructure, and deployment. Experience with tool/function calling, structured outputs, embeddings, retrieval, prompt design, and model evaluation. Strong product judgment and ability to move from ambiguous problem to shipped product quickly. Ability to work effectively in a fast-moving environment with ownership, collaboration, and high technical standards. Have a bachelor’s degree or equivalent in a related field to the offered position requirements Nice to Have Experience with LangGraph, LlamaIndex, OpenAI, Anthropic, Hugging Face, vLLM, or similar tools. Experience with agent memory, planning, multi-agent systems, browser automation, workflow automation, or AI copilots. Experience building eval pipelines, synthetic test cases, observability, guardrails, or AI safety systems. Experience with enterprise SaaS, productivity tools, developer tools, CRM, support, sales, finance, legal, or operations workflows. Experience working in early-stage, high-growth, or zero-to-one product environments Employee Pay Disclosures At Inflection AI, we aim to attract and retain the best employees and compensate them in a way that appropriately and fairly values their individual contributions to the company. For this role, Inflection AI estimates a starting annual base salary to fall within the range of $400,000.00 to $550,000.00, depending on a candidate’s qualifications and level of experience. This role also includes a meaningful equity component, allowing employees to share in the long-term success of the company. Benefits Inflection AI values and supports our team’s mental, emotional, financial and physical health. We are focused on building a positive, safe, inclusive and inspiring place to work. Our benefits include:  Robust medical, dental and vision options with employer contributions for HSA, FSA and DFSA 401k matching program  Flexible Time Off, 10 paid holidays, 5 days sick leave Parental, Medical and Family care leave  Generous cell-phone, wellness and office set up stipends  Support of country-specific visa needs for international employees living in the Bay Area