Founding Senior Full-Stack Engineer (Voice AI Platform)

Job location: San Carlos, CA (on-site)

About

We're not just automating calls—we’re transforming how the world communicates. Our AI voice agents are reshaping sales, support, and customer engagement for leading brands. Backed by Alt Capital, Y Combinator, and top-tier investors, we've raised $4.7M in seed funding and hit $14M ARR with just 12 people.

We’re one of the fastest-growing Voice AI startups and we're on a mission to become the standard for voice automation at scale.

About the Role

As a Founding Senior Full-Stack Engineer, you’ll shape the heart of the company AI’s voice automation platform, building scalable systems and intuitive interfaces that power millions of AI-driven conversations. You’ll work across the stack—leveraging React, TypeScript, and Node.js—to deliver fast, beautiful, and reliable solutions. Collaborating closely with the founding team, you’ll bridge backend architecture (like prompt orchestration and telephony integrations) with frontend experiences (such as dashboards and analytics tools), ensuring seamless customer onboarding and impactful user experiences. This high-impact role offers rapid feedback loops, customer collaboration, and the opportunity to define a category-leading product that transforms global communication.

Key Responsibilities

• Develop core features like prompt orchestration, dashboards, analytics, and telephony integrations.

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• Build scalable full-stack systems, from polished UIs to robust APIs and DevOps workflows.
• Lead projects from architecture to production, owning coding, deployment, and iteration.
• Create intuitive interfaces and APIs, enabling customers to activate in hours.
• Support customer onboarding, debug issues, and turn feedback into product enhancements.

You Might Thrive If You

• Have 2+ years of full-stack experience with React, TypeScript, Node.js, or Python.
• Hold a degree in CS, CE, or equivalent practical experience.
• Take ownership like a founder, proactively solving problems across the stack.
• Thrive in fast-paced settings, quickly adapting to new tools and challenges.

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• Communicate clearly, collaborating effectively in small, dynamic teams.

Job Details

• Job Type: Full-time, 70 hr/week (50 hr/week onsite with flexible hours + 20 hr/week work from home)
• Cash: 215k - 290k
• Equity: 0.4 - 0.6%
• Location: Redwood City, CA, US
• US Visas: Sponsors Visa & Green Card

Other Benefits

• 100% medical, dental, vision insurance coverage
• Unlimited breakfast, lunch, dinner, and snacks
• Gym and daily commute fee reimbursement
• Internet and phone bill covered

Compensation Philosophy

• Best Offer Upfront: Choose from three cash-equity balance options, no negotiation needed.
• Top 1% Talent: Above-market pay (top 5 percentile) to attract high performers.
• High Ownership: Small teams, >$1M revenue/employee, and significant equity.
• Performance-Based: Offers tied to interview performance, not experience or past salaries.