AI Engineer (Full-stack)

Location: San Francisco, CA (On-site)
Company Stage of Funding: Seed ($18.5M raised)
Office Type: On-site
Salary: $180,000 – $300,000 0.25%–0.75% Equity
Visa: O1, STEM OPT, H1B (fee-exempt only)

Company Description

Our client is building the infrastructure layer that teaches AI systems taste — enabling models to evaluate subjective quality across creative and aesthetic domains.

Their platform develops agent architectures, evaluation systems, synthetic data pipelines, embeddings infrastructure, and reinforcement learning environments that help foundation models and application-layer AI products better understand subjective judgment.

This is a rare opportunity to join an elite early-stage AI company building foundational infrastructure for one of the hardest unsolved challenges in artificial intelligence: teaching models nuanced human taste.

You’ll join a world-class team with backgrounds across frontier AI, search infrastructure, indexing systems, and large-scale model evaluation.

What You Will Do

Build and ship AI systems across backend and product surfaces

Design agent harnesses and self-improvement loops

Build memory systems for autonomous agents

Design synthetic data generation pipelines

Develop large-scale evaluation infrastructure

Build embedding and retrieval systems at production scale

Create scalable vector search infrastructure

Develop web crawling and scraping systems for visual datasets

Build inference serving systems

Develop APIs powering client-facing AI products

Build internal tooling for data operations

Develop external annotation tooling

Ship full-stack product experiences when needed

Build gamified user-facing experiences

Develop reward and leaderboard systems

Improve system reliability and performance

Work directly with leadership on technical architecture

Build core infrastructure from scratch

Ship rapidly in a highly ambiguous startup environment

Help define the technical direction of the company

Ideal Candidate Background

4 years of software engineering experience

Strong backend or full-stack engineering experience

Strong Python proficiency

Strong TypeScript / React proficiency

Experience building production AI systems

Experience working with LLM systems

Strong systems design fundamentals

Experience building scalable infrastructure

Strong product engineering instincts

Comfort with ambiguity

Strong ownership mindset

Fast execution velocity

Ability to operate independently

Strong technical curiosity

Excellent problem-solving ability

Comfort building greenfield systems

Strong Signals

Built agent systems in production

Designed evaluation pipelines

Synthetic data generation experience

Embeddings / vector DB experience

Built crawling / indexing infrastructure

Inference serving experience

LLM orchestration expertise

LangChain / PydanticAI / LlamaIndex experience

Built retrieval systems at scale

Experience with reinforcement learning environments

Early-stage startup experience

Open-source contributions

Strong side projects

Creative technology background

Experience at AI-native startups

Worked on subjective evaluation systems

Strong product taste

Experience at indexing/search companies

High experimentation velocity

Strong systems architecture judgment

Built from zero to production repeatedly

Compensation and Benefits

Base salary: $180,000 – $300,000

Equity: 0.25%–0.75%

Visa sponsorship available

High ownership environment

Direct technical influence

Early-stage equity upside

Greenfield AI infrastructure challenges

Work alongside elite AI engineers

Fast-moving engineering culture

Deep technical autonomy

Opportunity to shape foundational AI infrastructure

Why Join

This is an opportunity to work on one of AI’s most technically difficult frontier problems: teaching machines subjective judgment.

You’ll help build infrastructure that enables AI systems to evaluate quality, aesthetics, and taste across domains — work that sits at the intersection of infrastructure engineering, model evaluation, retrieval systems, and agent architectures.

If you want to build foundational AI systems from scratch, work with elite technical talent, and solve genuinely novel problems, this role offers exceptional technical leverage.