Senior Fullstack Engineer Monetization

About Us

At Lang Chain, our mission is to make intelligent agents ubiquitous. We build the foundation for agent engineering in the real world, helping developers move from prototypes to production‑ready AI agents that teams can rely on. We began as widely adopted open‑source tools and have grown to also offer a platform for building, evaluating, deploying, and operating agents ay Lang Chain, Lang Graph, Lang Smith, and Agent Builder are used by teams shipping real AI products across startups and large enterprises.

Millions of developers trust Lang Chain to power AI teams at companies like Replit, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, Vanta, and 35 % of the Fortune 500. With $125M raised at Series B from IVP, Sequoia, Benchmark, Capital

G, and Sapphire Ventures, we’re at a stage where we’re continuing to develop new products, growth is accelerating, and all team members have meaningful impact on what we build and how we work together. Lang Chain is a place where your contributions can shape how this technology shows up in the real world.

Lang Chain is hiring a Senior Fullstack Engineer to build the foundational product features and integrations that power user acquisition, rapid experimentation, and self‑serve expansion. This is a high‑impact 0→1 role on a newly formed team responsible for building growth systems from the ground up. You’ll work closely with product, design, GTM, and analytics to streamline activation, optimize packaging, and deliver a seamless growth story for developers and enterprise customers alike.

This role will be in person 5 days/week in New York City, San Francisco, or Boston.

• Work across our stack (React, Type Script, Python, Go) to deliver full‑stack product features that drive growth and retention
• Build flexible experimentation systems and processes capable of targeting diverse growth metrics
• Participate in data‑driven, rapid growth experiments across the user funnel from onboarding to monetization
• Design and ship new onboarding features and improvements that accelerate time to value
• Build growth levers including usage‑based guardrails, smart upgrade triggers, and contextual CTAs
• Collaborate closely with product, design, GTM, and analytics teams to identify, prioritize, and execute high‑impact growth opportunities

• Extensive fullstack software development experience using React, Type Script, and Go and/or Python
• Strong product intuition and a track record of working on monetization, pricing, or activation features
• Familiarity with usage metering, subscriptions, and internal tooling for pricing experiments
• Comfortable working with REST APIs, Postgres, Redis, and modern backend infra
• Startup DNA with the ability to thrive in fast‑paced, zero‑to‑one environments
• Self‑directed with an ownership mindset
• Bonus:
  Experience building for developers or product‑led growth platforms
• Bonus:
  Familiarity with LLMs, GenAI applications, or agentic frameworks

• We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks. Benefits include medical, dental, and vision coverage, flexible vacation, a 401(k) plan, and life insurance. Actual compensation and offerings will vary based on role, level, and location. Team members in the EU, UK, and APAC receive locally competitive benefits aligned with regional norms and regulations.
• Salary Range: $175,000‑$225,000 USD