Sr. Growth Engineer

Comfy•San Francisco, CA

7d•$160,000 - $220,000•Onsite

About The Position

Comfy is seeking a senior full-stack engineer to build and own the product-led growth engine for Comfy Cloud, which provides users with a zero-setup way to create with ComfyUI. This role involves identifying opportunities in signup, onboarding, activation, monetization, and retention, developing hypotheses, building and running experiments, and using the results to drive product decisions. The engineer will collaborate with Product, Design, Data, and Marketing teams, taking ownership of ambiguous growth problems from insight to production code. The primary output will be measurable improvements in user engagement, conversion to paying customers, and continued product usage, rather than just completed tickets.

Requirements

6+ years of software engineering experience
Strong across both frontend and backend development
Personally owned an activation, conversion, retention, or revenue metric—and can explain how your work moved it.
Run real product experiments from hypothesis through analysis, including experiments that failed or produced ambiguous results.
Comfortable building user-facing experiences in TypeScript and a modern frontend framework, as well as backend services and APIs.
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.
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.

Nice To Haves

Experience with Vue is useful, but strong fundamentals matter more than an exact stack match.
Built growth systems for a PLG, developer-tool, creator-tool, or usage-based SaaS product.
Worked on onboarding, templates, collaboration loops, referrals, pricing and packaging, subscriptions, credits, usage metering, or Stripe integrations.
Built or introduced experimentation infrastructure rather than only consuming an established platform.
Understand the unusual dynamics of growing an open-source product alongside a commercial cloud offering.
Use ComfyUI or other professional creative-AI tools and have opinions about making their power more approachable without flattening it.
Use AI development tools as a normal part of how you explore and ship.

Responsibilities

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.