Principal Fullstack Engineer (AI) - Boston

Location: Cambridge, MA (Eastern Time / UTC -4) Relocation package: Available Start date: ASAP Languages: English (required) ABOUT THE ROLE 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. WHAT YOU’LL DO • 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. WHAT WE’RE LOOKING FOR • 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. BONUS POINTS • 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. WHY THIS ROLE WILL PIVOT YOUR CAREER • Research pedigree: MIT CSAIL founders with deep AI and systems expertise. • Customer impact: Build products used by Fortune 500 clients. • Industry momentum: Alumni behind major acquisitions (MosaicML → Databricks, Run:AI → NVIDIA, W&B → CoreWeave). • Funding & growth: Oversubscribed seed round, next funding planned for 2026. • Ownership: Lead full stack architecture and mission-critical product features. • Engineering depth: Work on challenging scalability, performance, and AI infrastructure problems. BENEFITS • Competitive salary & equity options • Sign-on bonus • Health, Dental, and Vision • 401(k) Pragmatike is an Equal Opportunity Employer and is committed to providing equal employment opportunities to all applicants without discrimination. We recruit on behalf of our clients and prohibit discrimination and harassment based on race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state, or local laws. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation, and training.We are committed to a fair and inclusive hiring process. We process your personal data solely for recruitment purposes, in accordance with applicable privacy laws, and maintain reasonable safeguards to protect your information. Your data may be shared with our client(s) for hiring consideration, but will not be disclosed to third parties outside of the recruitment process.