Software Product Design Engineer

Build polished, thoughtful product experiences at YC

Y Combinator builds the software that runs YC — internal tools used by partners and founders, public products used by the broader startup ecosystem, and AI-powered systems that automate complex workflows. Our team is small, the impact is large, and we ship real product to real users frequently.

We’re looking for a Software Product Design Engineer — someone who lives at the intersection of design and engineering. You’ll design beautiful user experiences, translate high-fidelity mocks into production code, and proactively elevate existing interfaces with thoughtful detail and interactions.

What you’ll do

Design compelling, clear UI/UX and produce high-quality mocks that demonstrate strong product taste.

- Turn design mocks (yours or others’) into pixel-perfect, production-ready frontends using modern web tech.

- Iterate on existing interfaces by improving layout, interaction quality, motion, and design consistency.

- Work closely with engineers, partners, and stakeholders — you’ll own the design and implementation of features end-to-end.

- Rapidly prototype and “vibe code” to explore ideas, gather feedback, and iterate quickly.

- Contribute to design systems, component libraries, and patterns that raise the bar for frontend quality across YC.

- Stay close to users: talk to them, watch how they use the product, and improve the experience based on real signals.

What we’re looking for

- Strong UX and visual design skills with proven taste and craftsmanship.

- Frontend engineering experience — comfort building real UI in React, TypeScript, and modern CSS.

- Ability to move fluidly between design tools (Figma, etc.) and frontend code.

- A “get things done” mindset: you ship quickly, iterate based on feedback, and take ownership.

- Someone who cares deeply about polish — from typography and spacing to micro-interactions and transitions.

- Comfort with ambiguity: you’ll often define you...