Product Engineer (Full-Stack)

Location: New York, NY
Company Stage of Funding: Pre-Seed / Early Growth
Office Type: Hybrid — 4 days/week in-office in New York, NY
Salary: $150,000 – $190,000 + 0.25–1% Equity
Equity: 0.25–1% (willing to stretch for the right candidate)
Visa: No visa sponsorship or transfers — U.S. Citizens / Green Card holders only
Travel: No significant travel required

Company Description

Our client is building an AI-native platform designed to transform B2B SaaS sales through autonomous AI voice agents.

The company is an extremely early-stage startup founded in 2024 with a small, highly technical team of approximately 3 employees and approximately $2M in pre-seed funding.

The product enables AI voice agents to operate as full-cycle B2B SaaS sellers — qualifying prospects, answering complex product questions, conducting live product demonstrations through browser automation, and following up with prospects throughout the sales process.

The platform combines real-time voice AI, browser automation, LLM-powered workflows, data enrichment, and agentic systems to create an AI salesperson capable of operating continuously without human intervention.

The company has recently turned on revenue and is scaling extremely quickly, creating significant demand for the product. The team is building core technology around browser-use agents and real-time AI sales interactions rather than simply orchestrating existing AI tools.

This is an opportunity to become the first engineering hire outside the founding team, working directly with the founders to build the product from the ground up.

The role combines backend engineering, full-stack product development, AI/LLM engineering, browser automation, and direct customer collaboration in a highly autonomous startup environment.

What You Will Do

• Build backend services and APIs powering live AI sales conversations
• Design systems for session state, integrations, data pipelines, and real-time agent workflows
• Develop the browser-use agent that navigates and demos real software products during live sales calls
• Build AI agents capable of interacting with complex web applications in real time
• Develop LLM-powered workflows including prompts, tool use, and agentic execution flows
• Build infrastructure supporting real-time voice interactions and AI-powered sales experiences
• Work with WebRTC and real-time communication systems where needed
• Build and maintain product functionality using TypeScript, Node.js, Next.js, and React
• Develop integrations with external systems and customer products
• Build data pipelines and backend infrastructure supporting AI sales workflows
• Work directly with design partners to understand their needs and develop custom solutions
• Translate customer requirements into product features and reusable platform capabilities
• Identify patterns across customer implementations and feed learnings back into the core product
• Monitor real customer calls and use observed behavior to improve the product
• Iterate rapidly based on production feedback and customer interactions
• Ship production code frequently in a highly fast-moving environment
• Work directly with founders on architecture, product decisions, and technical priorities
• Own technical projects end-to-end from idea through production deployment
• Help establish engineering practices, architecture, and technical foundations as the first non-founder engineer
• Build scalable systems capable of supporting increasing customer and call volume
• Balance rapid experimentation with reliability and production quality
• Operate with extremely high autonomy in a small startup environment
• Help shape the company's technical direction and long-term product architecture

Ideal Candidate Background

Experience Requirements

• 2–5 years of professional software engineering experience
• Strong track record of shipping production software
• Experience building full-stack products with a strong backend focus
• Experience working in startup or high-ownership engineering environments strongly preferred
• Experience building customer-facing software products
• Experience working on products from early development through production
• Comfortable operating as an individual contributor without a dedicated PM layer
• Experience working directly with customers or design partners is strongly preferred
• Experience building AI-powered or real-time applications preferred
• Must be based in or willing to relocate to New York City

Technical Requirements

• Strong TypeScript and JavaScript engineering experience
• Strong backend development experience with Node.js
• Experience with Next.js and React
• Strong PostgreSQL/database experience
• Experience with Redis or similar caching/state-management systems
• Experience building and consuming APIs
• Hands-on experience building with LLMs or AI-powered applications
• Understanding of agentic workflows, tool use, or AI orchestration
• Experience with browser automation or browser-use systems is strongly preferred
• Experience with real-time applications or WebRTC is a strong plus
• Experience building data pipelines or backend data-processing systems
• Strong software engineering fundamentals including system design, debugging, testing, and deployment
• Ability to design reliable production systems
• Ability to move quickly from prototype to production
• Familiarity with Vercel AI SDK or similar AI application frameworks is a plus
• Ability to work across backend, frontend, AI, and infrastructure when required

Product & Customer Requirements

• Strong product instincts and ability to understand user needs
• Comfortable working directly with design partners and customers
• Ability to translate customer problems into technical solutions
• Strong interest in building user-facing AI products
• Comfortable watching real customer interactions and iterating based on feedback
• Ability to distinguish one-off customer requests from scalable product opportunities
• Strong understanding of how technical decisions affect user experience
• Comfortable making product and engineering decisions without extensive direction
• Excited by building products that are actively being used and sold in the market

Soft Skills

• Extremely high ownership and accountability
• Strong founder mentality
• Highly proactive and self-directed
• Comfortable operating without extensive structure
• Strong first-principles problem-solving ability
• Opinionated but open to feedback
• Excellent written and verbal communication
• Strong attention to detail
• Comfortable moving quickly and shipping frequently
• Low-ego and collaborative working style
• Highly curious about AI and emerging technology
• Comfortable taking responsibility for ambiguous technical problems
• Strong builder mentality
• Motivated by meaningful equity and early-stage company building
• Comfortable working in a highly demanding startup environment

Compensation & Benefits

• Base salary: $150,000 – $190,000
• Equity: 0.25–1%
• Company willing to stretch compensation for exceptional candidates
• Opportunity to become the first engineering hire outside the founding team
• Extremely high ownership over product and technical architecture
• Direct collaboration with founders
• Opportunity to build core AI and browser-use technology from the ground up
• Exposure to real-time voice AI, LLMs, agentic workflows, and browser automation
• Opportunity to work directly with design partners and customers
• Significant influence over engineering culture and technical direction
• High-impact role at an early-stage company with meaningful equity upside
• Fast-moving environment with rapid product iteration

Why Join

This is an opportunity to join an extremely early-stage AI startup as the first engineering hire outside the founding team and help build the next generation of B2B SaaS sales technology.

You’ll work directly with the founders to build AI voice agents that can qualify prospects, answer complex questions, conduct live product demonstrations through browser automation, and manage sales conversations end-to-end.

The role sits at the intersection of full-stack engineering, backend systems, real-time applications, LLMs, browser automation, and AI agents.

You’ll have significant influence over the product, architecture, and engineering culture while working directly with customers and seeing your code operate in real sales conversations.

If you enjoy high ownership, fast iteration, AI-native product development, working directly with founders and customers, and building from zero to one, this role offers exceptional technical scope and equity upside.