Senior Fullstack Engineer (AI)

Location: San Francisco office, on-site

Salary: $160,000–$220,000 per year plus equity

Company

Comfy builds an open-source AI creation engine and Comfy Cloud, a visual workflow platform for artists, filmmakers, game studios, designers, researchers, and VFX professionals.

What you will do

• Own growth experiments from opportunity discovery and hypothesis formation through implementation, instrumentation, analysis, and ship-or-kill decisions.
• Improve the Comfy Cloud journey across account creation, onboarding, first successful output, templates, local-to-cloud adoption, credits, upgrades, billing, collaboration, sharing, and retention.
• Build across the stack, including frontend experiences, backend services, APIs, data models, experiment assignment, billing logic, and lifecycle integrations.
• Improve activation, time to first value, free-to-paid conversion, retained usage, expansion, and revenue while protecting reliability, user trust, and compute economics.
• Query product data, investigate user behavior, speak with users, and use community feedback to guide product decisions.
• Build experimentation infrastructure such as feature flags, exposure logging, event instrumentation, health checks, and reusable patterns.

Requirements

• 6+ years of software engineering experience with strong frontend and backend development skills.
• Experience owning activation, conversion, retention, or revenue metrics and demonstrating measurable impact.
• Experience running product experiments from hypothesis through analysis, including failed or ambiguous experiments.
• Ability to build user-facing experiences with TypeScript and a modern frontend framework, as well as backend services and APIs.
• Ability to use SQL and product analytics tools to analyze funnels, cohorts, experiment results, and user behavior.
• Strong product judgment, UX focus, and ability to work independently in an ambiguous, high-ownership environment.

Nice to have

• Experience building growth systems for PLG, developer-tool, creator-tool, or usage-based SaaS products.
• Experience with onboarding, templates, collaboration loops, referrals, pricing, subscriptions, credits, usage metering, or Stripe integrations.
• Experience building experimentation infrastructure and understanding the growth dynamics of open-source products with commercial cloud offerings.
• Experience using hirify.global or other professional creative-AI tools, or using AI development tools in daily engineering work.

Culture & Benefits

• Small, intense team with high ownership, low ego, and a fast pace.
• Close collaboration with Product, Design, Data, Marketing, founders, users, and the Comfy community.
• Equity included in the compensation package.
• Work on an open-source AI ecosystem with millions of users and a commercial cloud product.