Principal Backend Engineer

COMPANY DESCRIPTION Extuitive is a Flagship Pioneering–backed startup reimagining product innovation for the AI era. Our mission is to revolutionize go to market for planning and execution for the agentic age. Based in Cambridge, MA, we operate like a special ops unit—fast-moving, data-driven, and relentlessly focused on impact. THE ROLE As a Principal Backend Engineer , you’ll be a technical leader responsible for architecting, building, and scaling the core backend systems that power our agentic platform. You’ll drive the design of high-throughput services, resilient data pipelines, real time agent clouds, and integrations with mission-critical third-party providers. You’ll translate complex requirements into robust, elegant systems that support rapid growth. You’ll be a key contributor to our technical strategy, helping evolve our platform architecture to maintain security and reliability as we scale. KEY RESPONSIBILITIES All things AI agents – from harness selection to prompt optimization and eval system, you’ll work side by side with your teammates to deliver best in class agent experiences. Own Core Backend Systems – Design, build, and maintain scalable services, APIs, and platform infrastructure. Ensure reliability, observability, and maintainability. Build and Maintain Large-Scale Data Pipelines – Architect and operate high-volume, resilient data pipelines for ingestion, transformation, and analytics. Lead Third-Party Integrations – Build and maintain integrations with external vendors, ensuring reliability, observability, and long-term maintainability. Influence Architecture & Best Practices – Shape backend architecture, coding standards, testing frameworks, CI/CD pipelines, and operational excellence. Wear Multiple Hats – Support DevOps, troubleshooting, or other platform needs when necessary. PROFESSIONAL EXPERIENCE & QUALIFICATIONS 8+ years of backend engineering experience. Experience with high velocity agentic coding under strict security requirements.