Founding Engineer​/React + Typescript + Node​/Hybrid; Flatiron, NYC

Founding Full-Stack Engineer (NYC, Hybrid)

A well-funded, early-stage startup is hiring a Founding Full-Stack Engineer to join a small, world-class team in New York City (Flatiron District). This hybrid role (4 days in-office) is ideal for an engineer who thrives in 0?1 environments and wants to own critical systems end-to-end while shaping the technical foundation of a high-impact product.

The company is building the future of scientific discovery — a personalized feed that connects experts to the breakthroughs that matter most. Backed by a Fortune 100 CEO and mission-driven investors, the mission is to become the global hub for credible scientific discourse.

This is a true founding engineer opportunity: part hands-on builder, part system architect, part product partner. You’ll design and ship scalable systems spanning intelligent ranking algorithms, semantic search and recommendation engines, predictive modeling systems, RAG pipelines, real-time data ingestion (e.g., Pub Med, arXiv), and social graph infrastructure. The ideal candidate loves building from scratch, moves quickly, and wants meaningful ownership from day one.

• 2–3+ years delivering production systems
• Strong proficiency in Type Script and Python
• Experience with modern frameworks (React, Next.js, Flask)
• Experience building scalable systems with Mongo
  
  DB and AWS (ECS)
• Familiarity with vector databases and ML / neural network systems
• Proven track record building 0?1 products (startups or side projects)
• High-agency mindset with strong ownership and execution ability
• Ability to work hybrid (4 days/week) in NYC

• Machine learning or predictive modeling experience
• Experience with semantic search or recommendation systems
• Experience with React Native / iOS development
• Startup or founding engineer experience
• Comfort leveraging AI-assisted development workflows

Tech Breakdown

• 35% Backend & Data Infrastructure (Python, Flask, Mongo
  
  DB, AWS ECS, real-time pipelines)
• 35% Frontend & Mobile (Type Script, React, Next.js, React Native)
• 30% ML Systems & Architecture (ranking algorithms, vector search, RAG, predictive models)

Daily Responsibilities

• 65% Hands-On Engineering & Code Contribution
• 20% System Design & Architecture
• 15% Collaboration with Founders, Product, and Design

This role is best suited for someone who wants to build foundational systems, influence product direction, and help define the technical DNA of an ambitious company from the ground up.