Senior Growth Fullstack Engineer (React/TS)

LangChain; New York (NY); On-site; USD 175,000 - 240,000; Full time

Benefits offered by this job

Medical, dental, and vision coverage

401(k) plan

In-office meals

Job summary

LangChain is hiring a Senior Fullstack Engineer to build 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.

Qualifications

• Strong mastery of modern frontend development (React, TypeScript, CSS/Tailwind).
• Solid fullstack fundamentals (REST/GraphQL APIs, Python/Go backends, database querying and caching).
• Exceptional UX intuition and a sharp eye for visual polish, micro-interactions, and developer-focused user journeys.

Responsibilities

• Lead projects across our stack (React, TypeScript) while working with backend APIs (Python, Go).
• Build polished, responsive user interfaces for onboarding, self-serve upgrades, and usage dashboards that delight users.
• Design and execute rapid, client-side UI experiments (A/B tests, feature flags) targeting key activation and conversion metrics.
• Partner with Product and Design to translate complex user journeys into simple, intuitive web experiences.
• Implement clean client-side event tracking and behavioral analytics to understand developer journeys.
• Build growth levers, including smart upgrade triggers, usage notifications and personalized, contextual experiences.

Skills

React

TypeScript

CSS/Tailwind

REST/GraphQL APIs

Python/Go backends

UX intuition

A/B testing frameworks

Growth engines

Startup DNA

Job description

LangChain is hiring a Senior Fullstack Engineer to build 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.