Principal Full Stack Engineer Jobs in Los Angeles, CA

ABOUT SINGLE GRAIN

Single Grain is a Revenue Marketing agency. We build pipeline-focused systems that compound — not campaigns that expire. We've helped 500+ companies, from venture-backed startups to the Fortune 500, drive measurable growth, influencing billions in revenue with a 3.2x average ROI.

Our portfolio includes:

• 
  Single Grain Agency — enterprise digital marketing services across SEO, paid media, creative, CRO, and AI-driven growth strategy.

• ClickFlow — our AI-powered content optimization platform that helps companies unlock hidden growth from their existing content by identifying high-impact SEO opportunities and improving rankings with AI insights.

• Karrot — a LinkedIn advertising and landing page platform built specifically for B2B companies running demand generation programs.

• Single Brain — the complete client operating layer: one agent interface for the human, one agent fleet commander for execution, an agent fleet of worker operators, and vertical specialists that handle the actual work.

We are evolving into a tech-enabled services (TES) company, where software, automation, and services combine to create leverage. Our CEO Eric Siu hosts the Leveling Up podcast and co-hosts Marketing School with Neil Patel, reaching millions of marketers and founders every month — a brand ecosystem most agencies don't have.

We are fully remote, and we operate as an AI-native team: every role at Single Grain is expected to use AI to increase speed, quality, and leverage.

ABOUT THE ROLE

Single Grain is at an inflection point: product must now drive revenue growth.

We're hiring a Senior Full Stack Product Engineer who builds like a founder and thinks like a product owner. You'll identify the highest-leverage product opportunities, ship them end-to-end, measure their revenue impact, and iterate until the numbers move. You'll use AI to compound your output and reduce cycle times.

Primary KPI: Increase Free Trial Paid Conversion from 20% to 40%.

This is not a ticket-execution role. There are no PMs handing you specs. You own initiatives from idea shipped measured optimized.

RESPONSIBILITIES

• 
  Own the conversion funnel. Audit the full free trial paid activation flow, map drop-off points with data, and ship improvements that move conversion rates.

• Ship production code independently. Build and deploy backend, frontend, and infrastructure changes without waiting for a dedicated DevOps team.

• Run structured growth experiments. Launch a minimum of two activation experiments per month by Month 6; instrument event analytics to measure impact.

• Build in-product expansion triggers. Design and ship a system that identifies expansion opportunities within the product and surfaces them to users.

• Operate AI-native workflows. Use AI (Claude, Cursor, and similar) for scaffolding, refactoring, and test creation. Document repeatable prompt workflows. Contribute to internal AI SOPs. Target: reduce dev cycle time by 40%+ within 12 months.

• Submit a revenue-focused roadmap within 30 days. Audit onboarding and activation, identify the top three revenue-impact friction points, and present a 12-month product roadmap with supporting data.

YOU MAY BE A GOOD FIT IF

• 
  3+ years of full stack engineering experience at an early-stage startup, with clear evidence of growth — promotions, expanded scope, or increased ownership over that time.

• You've built and shipped a product end-to-end that real users paid for or actively used. You can speak to what you personally built, the problems you hit, and how you iterated.

• You think in funnels, not features. You frame engineering decisions in terms of conversion, retention, and expansion — not just technical correctness.

• You're an AI Power User. You don't just use AI occasionally — you've built repeatable workflows with it, quantified the time it saves you, and actively look for more ways to apply it.

• You're comfortable with ambiguity and full ownership. You don't need a PM to scope your work. You can look at data, form a hypothesis, build a test, ship it, and measure the result.

• Bonus: experience in PLG (Product-Led Growth) environments, A/B testing frameworks, growth experiment design, or event instrumentation tools.

WHAT THIS ROLE IS NOT

• 
  Not a ticket-closer. If your best work environment is a well-groomed backlog with clear specs, this role will frustrate you.

• Not a junior-to-senior stepping stone. We need someone who already operates at senior level and is ready to own revenue outcomes from Day 1.

• Not a single-discipline specialist. Pure backend or pure frontend engineers who aren't comfortable spanning the full stack won't thrive here.

• Not a casual AI user. "I use ChatGPT sometimes" is not sufficient. This role requires AI-native workflows, not occasional experimentation.

BENEFITS

• Medical, dental, and vision insurance on the 1st of the month after you join

• 401(k) with 100% match up to 3% of your salary

• $50K life insurance policy, paid 100% by the company

• 12 weeks of paid family leave, effective after the first year of employment

• Flexible Unlimited Paid Time Off

• $100 utilities stipend, paid out as an extra $50 per paycheck

• $60 UberEats credit each month

• A MacBook

• $500 WFH office reimbursement

• Fully remote — work from anywhere