Founding Engineer (Frontend + Design)

A fast-moving, seed-stage AI startup - part of the Y Combinator S25 batch - is hiring its first Founding Engineer (Frontend + Design). This is a rare opportunity to own the entire frontend stack for native macOS and iOS apps from the ground up, with a design-first, pixel-perfect philosophy at the core of everything you build.

As an early team member, you’ll work directly alongside the founders and have outsized influence on product strategy, user experience, and company direction. The product sits at the intersection of AI and human relationships - helping people stay on top of their communications, tasks, and personal organization through an intelligent, proactive assistant.

This role requires on-site presence in San Francisco and a high-intensity, startup-founder mindset., * Own frontend architecture, networking, and UI animations for native iOS and macOS apps.

• Deliver pixel-perfect, accessible, design-focused UI across native Apple platforms.
• Conduct user research and engage directly with users to inform product decisions.
• Collaborate closely with design and backend teams to ship cohesive, polished experiences.
• Contribute to product strategy and advocate strongly for the end user.
• Build performant, maintainable code aligned with established design systems and SwiftUI patterns.

Must-haves:

• Strong native Swift experience with MVVM architecture and the latest SwiftUI patterns - this is a dealbreaker requirement.
• Proven ownership of frontend architecture, networking, and UI animations for iOS/macOS apps.
• Experience with design tooling (e.g., Figma) and contributing to or working within design systems.
• Pixel-perfect, design-focused approach with strong attention to detail and accessibility.

Strongly preferred:

• Experience working at a founding-stage or early startup.
• Ability to conduct user research and translate user feedback into product decisions.
• Some exposure to the backend stack: Python, FastAPI, Supabase, AWS ECS, and Lambda.
• Strong CS fundamentals and a demonstrated track record of solving hard, complex problems.
• Located in San Francisco with the ability to work on-site; comfortable with a high-intensity work environment.

• Salary: $160,000 - $240,000 USD annually, depending on experience.
• Early equity commensurate with founding team member status.
• Visa sponsorship: Not available.