Founding Staff Software Engineer (Full-Stack + Mobile)

Founding Staff Engineer (Full-Stack + Mobile) — New York City (Onsite)

Compensation: $250K–$350K base + significant equity

Location: New York City — onsite 5 days/week

Visa: Case-by-case support

Type: Full-time — 1 headcount

Overview

A fast-growing early-stage startup in the consumer health and AI space is looking for a Founding Staff Engineer to partner directly with the CTO. This role is ideal for someone who thrives in 0→1 environments, wants to influence technical direction from day one, and enjoys owning systems across the entire stack — from mobile to backend to infrastructure.

The product already has strong market traction, rapidly growing daily active users, paying subscribers, and clear product-market fit. The current engineering team is extremely small, so you will directly shape the engineering culture, architecture, and speed of execution for years to come.

If you enjoy solving real consumer problems, building polished mobile experiences, scaling systems fast, and working closely with product and design, this is a rare opportunity to join a breakout startup early.

What You’ll Own

• Own the core architecture across the stack — backend services, APIs, mobile performance, observability, and infrastructure.
• Scale high-traffic systems to support rapid user growth (currently tens of thousands of weekly active users and rising).
• Build world-class mobile experiences using React Native, leveraging native-level performance optimizations.
• Develop backend services using Node.js or Python that are fast, reliable, and secure.
• Collaborate closely with product and design to deliver intuitive, high-impact consumer-facing features.
• Define engineering best practices across testing, CI/CD, instrumentation, and deployment.
• Own 0→1 initiatives with autonomy, urgency, and sound technical judgment.
• Set the engineering culture, standards, and roadmap alongside the founding team.

Ideal Experience

• 6+ years of software engineering experience across full-stack or mobile engineering.
• Proven experience shipping and scaling consumer mobile apps used by thousands of users.
• Strong experience in React Native and TypeScript, with native iOS/Android experience preferred.
• Deep expertise with backend systems, APIs, architecture, and infrastructure (Node.js or Python).
• Ability to turn Figma designs into high-fidelity, production-quality mobile interfaces.
• Solid understanding of app performance, animations, and UI polish (Reanimated, Lottie, Rive, etc.).
• Experience operating as a founding engineer, staff engineer, tech lead, or previous technical founder is a major plus.
• Background in AI-driven products, consumer health, behavior-change apps, or wellness is helpful but not required.

What You Bring

• A product-minded mindset — able to balance technical trade-offs with user experience.
• Ability to work cross-functionally with founders, design, and product.
• Strong architectural instincts and the ability to move fluidly between mobile, backend, and infrastructure.
• A bias toward shipping fast, iterating quickly, and owning outcomes end-to-end.
• Comfort working in a high-speed, high-ambiguity early-stage environment.
• A desire to help build a category-defining consumer product from the ground up.

Requirements

• Must be based in New York City or willing to relocate.
• Must be comfortable working onsite 5 days/week (no remote or hybrid options).
• Ability to travel into NYC for interviews if needed (relocation support provided for final onsite stage).

Why This Role Stands Out

• Join a product that already has strong traction, revenue, and a fast-growing user base.
• Work directly with the CEO, CTO, and founding team.
• Huge ownership — your work will immediately impact real users at scale.
• Significant equity with long-term upside.
• Build in one of the fastest-growing consumer health categories in the US.
• Help define the technical foundation and culture of a soon-to-be iconic consumer brand.