The Role

Comfy has millions of users and one of the largest open-source ecosystems in generative AI. Comfy Cloud gives that community a zero-setup way to create with ComfyUI, but we are still early in building the product-led growth engine around it.

We're looking for a senior full-stack engineer to own that engine.

You will find the biggest opportunities in signup, onboarding, activation, monetization, and retention; turn them into hypotheses; build the experiments yourself; and use the results to decide what we ship, iterate, or kill.

This is not a role where a PM hands you a finished specification. You will work closely with Product, Design, Data, Marketing, and the founders, but you should be able to take an ambiguous growth problem from data and user insight all the way to production code and a defensible decision.

Your output is not tickets completed. It is more users reaching meaningful value, becoming paying customers, and continuing to create with Comfy.

What You'll Do

Own experiments end to end: identify an opportunity, form a hypothesis, define the primary metric and guardrails, build the experience, instrument it, launch it, analyze the result, and make the ship-or-kill decision.

• Improve the full Comfy Cloud journey, including account creation, first workflow, first successful output, templates, local-to-cloud adoption, credits, upgrade flows, billing, collaboration, sharing, and retention.
• Build across the stack-from polished frontend experiences to backend services, APIs, data models, experiment assignment, billing logic, and lifecycle integrations.
• Own measurable product outcomes such as 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 yourself and investigate user behavior without waiting for an analyst to translate it for you.
• Talk with users and learn from Comfy's community when quantitative data does not explain what is happening.
• Build the minimum experimentation infrastructure needed to move quickly with trustworthy results: feature flags, exposure logging, event instrumentation, experiment health checks, and reusable patterns.
• Turn successful experiments into durable, production-quality product experiences.
• Raise the growth-engineering bar by documenting what the team learns and helping other engineers run better experiments.

You Might Be a Good Fit If You

• Have 6+ years of software engineering experience and are strong across both frontend and backend development.
• Have personally owned an activation, conversion, retention, or revenue metric-and can explain how your work moved it.
• Have run real product experiments from hypothesis through analysis, including experiments that failed or produced ambiguous results.
• Can work without a detailed specification. You know how to combine data, user insight, product judgment, and technical constraints into a sensible next bet.
• Are comfortable building user-facing experiences in TypeScript and a modern frontend framework, as well as backend services and APIs. Experience with Vue is useful, but strong fundamentals matter more than an exact stack match.
• Can use SQL and product analytics tools to explore funnels, cohorts, experiment results, and unexpected behavior.
• Understand experiment fundamentals: assignment, exposure, primary metrics, guardrails, sample-size tradeoffs, novelty effects, and segmentation.
• Have excellent product judgment and care about UX quality-not just whether the code works.
• Move quickly while knowing when an experiment can be lightweight and when billing, identity, privacy, or core product architecture demands more rigor.
• Thrive in a small, intense team with high ownership, low ego, and a fast clock.

Bonus Points

• You have built growth systems for a PLG, developer-tool, creator-tool, or usage-based SaaS product.
• You have worked on onboarding, templates, collaboration loops, referrals, pricing and packaging, subscriptions, credits, usage metering, or Stripe integrations.
• You have built or introduced experimentation infrastructure rather than only consuming an established platform.
• You understand the unusual dynamics of growing an open-source product alongside a commercial cloud offering.
• You use ComfyUI or other professional creative-AI tools and have opinions about making their power more approachable without flattening it.
• You use AI development tools as a normal part of how you explore and ship.

What This Role Is Not

• A marketing-engineering role limited to landing pages and SEO.
• An analytics-engineering role focused primarily on pipelines and dashboards.
• A feature factory where Product decides what to build and Data decides whether it worked.
• A research role that produces experiment ideas for other engineers to implement.

What Success Looks Like

In your first three months, you will understand the Comfy Cloud funnel, establish trustworthy baselines, identify the largest points of friction, and ship your first experiments.

Within six months, you will own a repeatable experiment cadence, have produced measurable improvements to at least one company-level growth metric, and have made it substantially easier for the team to launch and evaluate new growth ideas.

Within twelve months, Comfy will have a stronger self-serve growth engine-and a body of accumulated knowledge about what helps creators discover value, convert, and stay-because of the systems and experiments you built.