Senior AI Product Designer

Location: NYC (Hybrid, 3x/week)

Compensation: $180k–$200k base salary range based on level and experience, plus a generous pre-IPO equity package

About Hearth

Hearth is the AI growth system for local home improvement small businesses. We build revenue-critical software for home improvement contractors — the roofers, HVAC techs, and builders who keep America running.

Our platform helps real business owners win more jobs, protect profit margins, and manage homeowner relationships professionally so they can build generational companies for their families and communities.

We are now building the next layer: a personal AI employee for every small business in the trades focused on autonomously generating sales for America’s home improvement pros. An assistant who answers every call 24/7, qualifies leads, books appointments, follows up on quotes and estimates, and helps small business owners go from missing half of their business to capturing all of it.

With 15,000+ paying customers, default profitability, and backing from some of the world’s best investors (Founder’s Fund, 8VC, Human Capital, etc.), Hearth is focused on bringing AI to the trades.

The Opportunity

We are searching for the right Senior Product Designer who will help bring AI to the trades. You will own how millions of small business contractors and homeowners experience Harper - Hearth’s AI digital employee. This is a high-impact role that defines how a massive, underserved industry experiences AI for the first time.

You will run rapid validation and user testing with real contractors, design and ship experiences that inflect the growth rate of the business, and ultimately translate powerful technology into experiences so intuitive that a roofer in 100°F heat can use them between jobs in under five minutes.

The right person for this role is a true builder - someone who is high agency, high urgency, and wants to have a meaningful impact. You are a true partner to engineers, accelerating time to ship and injecting the voice of the customer to unblock the team. You spend a quarter of your time with customers, and the rest of your time turning what you learn into experiments that drive commercial impact.

What You'll Do:

• Harper AI experience end-to-end. Onboarding and activation flows, the Message Center / Stream UI, intent previewing and editing, and every AI-powered touchpoint across web, mobile, and messaging…all designed to drive real commercial outcomes in a simple, intuitive way.
• User research operations. Run weekly rapid interviews with contractors, test prototypes in the field, and synthesize qualitative signals into product decisions the entire team can act on. You’ll spend 25%+ of your time with customers.
• AI design system and interaction patterns. Build and maintain production-grade components for AI interfaces that reduce engineering ambiguity and accelerate the team.
• Cross-functional translation. Turn product outcomes into acceptance criteria, engineering tickets with required instrumentation events. You’re the connective tissue between product, engineering, and the customer.
• Experimentation engine. Draft hypotheses, define success metrics, ship lightweight A/B and feature experiments, analyze impact, and iterate in days, not months. You own the full cycle from insight to shipped experiment to measured result.

Your First 90 Days:

• Weeks 1–2: Audit the Harper UX end-to-end — onboarding funnel, Message Center, product demos. Deliver a prioritized list of 3 experiments with hypotheses, target metrics, and required engineering effort.
• Month 1: Ship your first high-impact A/B or feature experiment with a measurement plan. Get in front of customers and deliver a customer insight that directly informs the roadmap.
• Month 2: Scale experimentation cadence. Work closely with engineers and leadership to deliver on the product roadmap. Begin mapping the AI design system and deliver multiple explorations for team review.
• Month 3: Stabilize the experimentation engine, formalize the design system, and establish the research and measurement rituals that will compound from here.

Who You Are: