Technical Cofounder

Sandfox | Technical Cofounder

Location: San Francisco Bay Area 

Format: In-office 4 days a week with flexibility for the occasional remote days

The Mission

Sandfox is building an adaptive buyer-led discovery platform for enterprise B2B.

Our vision is a world where every business interaction adapts to buyer context, where companies understand what buyers are trying to accomplish and deliver the information, guidance, and experiences they need.

Today, most B2B buying experiences are static. Websites, content hubs, and campaigns deliver the same experience regardless of who the buyer is or what they need. Sandfox transforms fragmented buyer data into structured intelligence that powers adaptive experiences, helping companies deliver relevance instead of noise.

Sandfox is a portfolio company of super{set}, a venture studio that conceives, funds, and builds AI-native companies from formation through scale. We work alongside founders as operators, helping shape companies from day one.

We're a small, early-stage team building something that doesn't exist yet in the market. The work is hands-on, the problems are difficult, and the opportunity to shape both product and company from the ground up is significant.

Role

We're looking for our first engineering hire: a Founding Engineer who will shape both the product and the technical foundation of Sandfox.

You'll work directly with the founder to turn product vision into production software, establish engineering standards, and define how adaptive buyer experiences should work in practice.

This role goes beyond engineering execution. We're building a new category of software where user experience, information architecture, AI orchestration, and interface design are deeply intertwined. You'll help shape not only how the platform works, but how it feels.

We're looking for someone energized by ownership, ambiguity, and the opportunity to build elegant solutions to complex problems from the ground up.

WHY THIS ROLE MATTERS

The technical challenge is only part of what we're solving. Sandfox sits at the intersection of AI, buyer psychology, workflow design, and user experience. The winners in this category won't simply have the best models or infrastructure. They'll create experiences that feel intuitive, adaptive, and genuinely useful. As Sandfox's first engineering hire, you'll help define what the next generation of B2B buying experiences looks like.

WHAT YOU’LL OWN

You'll own the technical foundation of Sandfox, including:

• AI-powered workflows and user experiences that transform buyer context into adaptive discovery journeys and seller intelligence.
• Product quality and design craftsmanship across the customer experience, from first interaction through ongoing usage.
• Production systems that combine retrieval, reasoning, evaluation, and user feedback
• Scalable backend services and data pipelines
• Customer-facing applications used by enterprise teams
• Internal tooling, infrastructure, and deployment systems that support rapid iteration

This role spans the entire stack. One week you may be designing adaptive buyer experiences and customer-facing workflows; the next, building AI systems, evaluation frameworks, or infrastructure that powers them at scale.

WHAT SUCCESS LOOKS LIKE

In the first 6–9 months:

• Ship experiences customers describe as intuitive, elegant, and genuinely helpful
• Establish the technical architecture and engineering standards of the company
• Build systems that support rapid product iteration without sacrificing reliability
• Partner closely with the founder on roadmap, architecture, and technical decision-making
• Help establish a product culture where design quality, usability, and customer experience are considered as important as technical execution

WHAT YOU BRING

Must Have

• Experience building and shipping production systems across multiple layers of the stack.
• Experience building AI-powered features used by real customers, with an understanding of reliability, evaluation, latency, and cost trade-offs.
• Strong product instincts and exceptional design taste. You have a demonstrated ability to recognize what makes software intuitive, elegant, and enjoyable to use.
• Experience translating ambiguous ideas into polished user experiences and workflows.
• Worked directly with customers.
• A track record of operating with autonomy in early-stage or fast-moving environments.
• Excitement for ownership and building alongside founders from the ground up.

Familiarity with technologies such as Python, Go, TypeScript, React, PostgreSQL, Redis, ClickHouse, AWS, and Docker is valuable, though we care more about learning agility and architectural judgment than expertise in any specific technology.

Nice to Have

• Experience as an early engineer at a startup
• Experience building SaaS products
• Experience building polished product experiences at companies known for design quality and product craftsmanship.
• Experience working closely with product designers or independently driving UX decisions.
• Experience with retrieval systems, search, knowledge management, or AI-native products
• Prior experience hiring or mentoring engineers

What You Get

• A defining role as the first engineer at an early-stage AI company.
• Direct partnership with the founder on product and technical strategy.
• Meaningful ownership and the opportunity to shape both the product and the engineering culture from day one.