Principal FS Engineer (AI)

Pragmatike•Cambridge, MA

3d•Onsite

About The Position

Pragmatike is hiring on behalf of a fast-growing AI startup recognized as a Top 10 GenAI company by GTM Capital, founded by MIT CSAIL researchers. We are searching for a Senior Full Stack Engineer (Node.js + React) with strong hands-on experience building scalable, high-performance web applications powering complex, data-intensive AI products used by Fortune 500 customers. This role is ideal for an engineer who enjoys owning features end to end—from backend architecture to polished frontend delivery—someone who can design APIs, build scalable services, craft intuitive user interfaces, and ship production-ready features at scale.

Requirements

5+ years of experience as a Full Stack Engineer.
Strong proficiency in Node.js (Express, NestJS, or similar frameworks).
Strong proficiency in React and TypeScript in production environments.
Experience designing RESTful APIs and working with databases (PostgreSQL, MongoDB, or similar).
Solid understanding of modern web architecture and distributed systems fundamentals.
Experience building scalable, secure, and high-performance applications.
Familiarity with cloud environments (AWS, GCP, or Azure).
Comfortable owning features and shipping to production independently.
Strong collaboration skills across product, design, and backend/ML teams.

Nice To Haves

Experience building data-heavy dashboards or real-time web applications.
Familiarity with modern state management solutions (Redux, Zustand, React Query).
Experience with event-driven architectures or message queues.
Exposure to AI-driven or ML-powered products.
Startup experience or comfort working in fast-moving, ambiguous environments.

Responsibilities

Design, build, and maintain scalable full stack applications using Node.js, React, and TypeScript.
Architect and develop robust backend services, APIs, and data models.
Build modern, production-grade web interfaces with React.
Own features end to end, from technical design and implementation to deployment and production support.
Optimize performance across the stack (frontend rendering, API latency, database queries).
Collaborate closely with product, design, and AI/ML teams to ship user-facing features.
Establish best practices around testing, code quality, observability, and CI/CD.
Improve overall system architecture, scalability, and developer experience.
Debug and resolve production issues across both frontend and backend systems.