Founding Engineer (Full Stack) ($150k-$225k + Equity) at Neptune

About the role

The role of the Founding Engineer (Full Stack) at Neptune involves architecting and building the core AI engine and product experience from the ground up. This high-impact role sets the technical foundation while shipping features that directly influence how couples build wealth.

Responsibilities

• Design and ship the "Neptune brain," a shared context engine that manages a couple's full financial and legal history.
• Develop conversational AI and LLM-powered workflows that translate complex model outputs into high-credibility user experiences.
• Own features end-to-end across the stack, from backend architecture and Plaid integrations to frontend execution in Next.js.

Requirements

• Has 4–7 years of full-stack experience with a track record of shipping impactful production features in high-trust environments.
• Demonstrates deep "AI-native" intuition, using LLMs as force multipliers and understanding their performance across sensitive financial tasks.
• Possesses early-stage startup DNA, characterized by extreme agency, product-thinking, and the ability to thrive in an in-office NYC environment.

Qualifications

• Expertise in full-stack development, including backend architecture, frontend execution, and integration with third-party services like Plaid.
• Experience with large-scale data management and processing, particularly in the context of financial and legal data.
• Strong understanding of machine learning and natural language processing, with a focus on ethical and privacy considerations.
• Ability to work in a fast-paced, collaborative environment and adapt quickly to changing priorities.

Skills

• Proficiency in JavaScript, TypeScript, and Next.js.
• Experience with Python and other programming languages relevant to AI and data science.
• Knowledge of database systems and cloud platforms such as AWS or GCP.
• Excellent problem-solving skills and the ability to work independently and collaboratively.

Benefits

• Massive ownership and founding-level equity.
• Opportunity to work with cutting-edge LLMs on high-trust, real-world financial and legal use cases.
• Join a world-class founding team including the creator of Google Forms and the founding engineer of Stripe.
• Work in a dynamic, supportive environment with a strong emphasis on innovation and collaboration.

Pay

$150k - $225k + Equity

Schedule

Full-time, Monday to Friday, 9 AM to 6 PM EST