Founding Engineer
Arcadia, San Francisco, CA, United States
A high-growth, innovative startup is looking for a Founding Engineer to build software focused on understanding how LLMs form opinions about companies, products, and information online.
You’ll work across product, research, and infrastructure, owning problems end-to-end, from identifying customer insights to shipping production systems. As an early engineer, you’ll have significant ownership in shaping the product, architecture, and engineering culture. This role focuses on building systems that analyze model behavior, uncover the sources and reasoning behind responses, and help organizations better understand and influence those outcomes.
If you're excited about LLMs, interpretability, agentic systems, and building entirely new types of developer tooling, this role offers the chance to work at the frontier of how AI systems interact with real-world information.
What You’ll Do
Build full-stack product features from concept to production
Design systems that probe and analyze LLM behavior at scale
Develop tooling to understand model reasoning patterns, sources, and biases
Build infrastructure for large-scale model testing and experimentation
Work closely with customers to translate insights into product capabilities
Collaborate with leadership on product direction and technical architecture
Help define best practices for AI-assisted and agentic development workflows
What You Bring
3+ years of professional software engineering experience
Experience with React, Python, AWS, and Terraform
Comfort working across frontend, backend, and infrastructure
Ability to own problems from idea to shipped product
Curiosity about how large language models behave and how they can be studied or influenced
Nice to Have
Experience building LLM-powered or agentic systems
Background in machine learning, NLP, or AI tooling
Startup experience or self-driven technical projects
Experience speaking directly with customers to inform product development
Why This Role Is Interesting
Work on new technical challenges around analyzing and interacting with AI systems
Help shape the early engineering culture at a fast-moving startup
Build systems at the intersection of AI research, developer tooling, and real-world applications
Significant ownership over product direction and technical architecture
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You’ll work across product, research, and infrastructure, owning problems end-to-end, from identifying customer insights to shipping production systems. As an early engineer, you’ll have significant ownership in shaping the product, architecture, and engineering culture. This role focuses on building systems that analyze model behavior, uncover the sources and reasoning behind responses, and help organizations better understand and influence those outcomes.
If you're excited about LLMs, interpretability, agentic systems, and building entirely new types of developer tooling, this role offers the chance to work at the frontier of how AI systems interact with real-world information.
What You’ll Do
Build full-stack product features from concept to production
Design systems that probe and analyze LLM behavior at scale
Develop tooling to understand model reasoning patterns, sources, and biases
Build infrastructure for large-scale model testing and experimentation
Work closely with customers to translate insights into product capabilities
Collaborate with leadership on product direction and technical architecture
Help define best practices for AI-assisted and agentic development workflows
What You Bring
3+ years of professional software engineering experience
Experience with React, Python, AWS, and Terraform
Comfort working across frontend, backend, and infrastructure
Ability to own problems from idea to shipped product
Curiosity about how large language models behave and how they can be studied or influenced
Nice to Have
Experience building LLM-powered or agentic systems
Background in machine learning, NLP, or AI tooling
Startup experience or self-driven technical projects
Experience speaking directly with customers to inform product development
Why This Role Is Interesting
Work on new technical challenges around analyzing and interacting with AI systems
Help shape the early engineering culture at a fast-moving startup
Build systems at the intersection of AI research, developer tooling, and real-world applications
Significant ownership over product direction and technical architecture
#J-18808-Ljbffr