Founding Engineer - Full Stack
Build the future of AI interpretability and agentic workflows at a fast-growing, YC-backed startup with top-tier compensation and equity.
Location: San Francisco, CA
About the Role:
We are seeking 1-2 "Founding Engineers" to join one of our client's team on full-time onsite basis. Our client's company is a rapidly scaling venture-backed startup helping companies discover and change how AI models perceive brands—essentially applying psychology to LLMs to drive leads and influence content, pricing, and product strategies.
As a Founding Engineer, you will help to address bandwidth issues, expand core product features, and build the future of AI interpretability. This role requires high independence, exceptional communication skills, and the ability to own features end-to-end—from initial research and infrastructure to shipped product.
What You'll Do?
Platform Development: Build and extend a universal context management platform that powers agentic workflows across customer data, communications, and deliverables.
AI Interpretability: Apply black-box AI interpretability techniques to reverse-engineer how LLMs form opinions about brands and their competitors.
End-to-End Ownership: Take full ownership of features from understanding customer needs through research, infrastructure, and production deployment.
Engineering Practices: Help define new engineering team patterns and practices around agentic coding tools (such as Claude Code).
Custom Automation: Build internal automation and custom software for clients using AI agents with full company context.
To Succeed in This Role:
Experience: 1–5 years of full-stack engineering experience, with a preference for previous startup experience and non-traditional backgrounds. Exceptional communicators with slightly less experience will also be considered.
Core Technical Stack: Mandatory proficiency in Python and React. Backend and infrastructure experience is heavily prioritized over frontend design.
Domain Expertise: Prior experience with agentic AI systems and LLMs is required. Familiarity with Terraform, AWS, and modern tooling is a strong plus.
Soft Skills: Exceptional communication, strong problem-solving abilities, independence, and a low-ego, team-oriented mindset.
Compensation & Logistics:
Salary: Competitive base salary (dependent on experience; open to the higher end for truly exceptional candidates).
Equity: 0.3% – 1.5% equity.
Location: On-site (5 days a week) in San Francisco, CA.
Visa Status: No new visa sponsorships are available. However, the company will support O-1 transfers and H-1B transfers (providing a letter of support for existing visa holders).
About Sperton
This Position is Sponsored by Sperton Global, a recruitment and consulting company with an international reach. We are committed to helping our clients achieve success in their hiring processes, finding the right people for the right positions.
- Department
- Information Technology
- Locations
- United States
- Employment type
- Full-time
- Job location
- San Francisco, CA
Colleagues
Workplace & Culture at Sperton
At Sperton, we believe that great results come from great people.
Our culture is built on trust, collaboration, and a shared passion for delivering quality in everything we do.
We are a Norwegian-owned international company with colleagues across Europe, Asia, and the USA, working together seamlessly across time zones and cultures. Our teams are diverse, yet united by the same goal — to connect people and companies in meaningful ways.
We value openness, initiative, and continuous learning. Everyone at Sperton is encouraged to take ownership, share ideas, and challenge existing ways of working to make our solutions even better.
Even though we operate globally, our approach is personal. We take pride in creating a supportive and inclusive environment where people feel heard, respected, and motivated to grow — both professionally and personally.
