Full-stack engineer

Location: San Francisco, CA

Department: Engineering

What you'll do:

• Build scalable, production-grade full-stack systems that serve millions of users with high reliability and performance
• Develop robust backend API services (Python) that power core product functionality and data workflows
• Design and implement intuitive, high-quality frontend experiences — with strong attention to design, usability, and customer experience
• Architect and manage deployments on GCP and Kubernetes, ensuring reliability, observability, and scalability
• Design and maintain storage backends (databases, object storage, caching layers) to support high-throughput, data-intensive systems
• Own features end-to-end — from product conception and system architecture to deployment, monitoring, and iteration
• Collaborate closely with customers and internal teams to ship quickly, incorporate feedback, and continuously improve the product

What we look for:

• Strong experience building and shipping full-stack web applications, with the ability to move fluidly between frontend and backend
• Proficiency in modern frontend technologies (TypeScript, React, modern CSS, Vercel) and backend development (Python or similar), with experience operating production systems
• Hands-on experience deploying and operating systems on GCP and Kubernetes, with strong infrastructure fundamentals
• Experience designing and managing storage systems (SQL/NoSQL databases, object storage, caching layers)
• Interest in AI systems and enthusiasm for building tools that help engineers work more effectively with AI agents
• High bar for product quality, performance, and user experience — balanced with the ability to move quickly and iterate
• Generalist mindset with comfort working across infrastructure, APIs, data models, UI layers, and deployment environments
• Strong ownership mentality and ability to thrive in a fast-paced startup environment
• Bachelor’s degree in Computer Science, Engineering, or related field (or equivalent practical experience)

Our Core Values:

• Customer Obsession - We start with the customer and work backwards. We aim to earn trust through consistent delivery, thoughtful listening, and by obsessing over customers.
• Intellectual Honesty - We operate with high trust and low ego. Ideas matter more than titles, and we communicate openly and directly while assuming good intent, even in strong disagreement.
• Bias for Action - We set high standards and move quickly to meet them. We prefer building and learning with customers over debating in the abstract, and we iterate based on real feedback.
• Extreme Ownership - We take responsibility for outcomes, not just tasks. Ownership means seeing problems through to completion and ensuring solutions truly work in practice.

Benefits and perks

• Competitive salary plus meaningful equity package
• Comprehensive medical benefits and generous PTO
• Flexible work arrangements
• Direct impact on company direction and technical decisions
• High ownership and the opportunity to make a career-defining impact

• Visa sponsorship

As a founding member, you’ll help define the technical foundation of NeoSigma. Your scope will grow with the company, from owning core systems end-to-end to shaping architecture, hiring, and engineering culture. This role has a natural path toward technical leadership or engineering management as the team scales.

About the Company

About Us

NeoSigma is a product-driven research lab building the intelligence layer that helps close the feedback loop between your customers, products, and AI systems.

We are a small, intensely technical team of researchers and engineers who have trained frontier-scale models and widely used AI products and agents at Parallel Web, Essential AI, MIT, Apple, and Amazon.