Growth Engineer

Lully

Growth Engineer at HappyRobot responsible for migrating site infrastructure to a self-hosted environment. Building scalable code infrastructure to enhance user experience and analytics for AI-powered platforms.

Posted 7/6/2026full-timeBarcelona • 🇪🇸 SpainMid-LevelSeniorWebsite

Tech Stack

Tools & technologies

JavaScriptNext.jsNode.jsReactTypeScript

About the role

Key responsibilities & impact

Lead the engineering effort to migrate our marketing site and customer funnels out of Webflow and into an ultra-fast, self-hosted frontend built on Next.js/Vercel and Payload CMS.
Architect dynamic, programmatic landing page templates for high-value VIP accounts that pull tailored assets, logos, and account metrics flawlessly without layout shifts or visual "flicker".
Implement best-in-class, in-platform tracking that diagnoses existing data gaps and implement robust tracking so our sales teams have total visibility into what accounts are doing inside our platform.
Seamlessly pipe event data and user traits from PostHog and outbound tooling directly down into Salesforce CRM, optimizing API payloads to maintain immaculate CRM data hygiene.
Build and maintain our growth experimentation infrastructure.
Design, launch, and analyze complex server-side A/B tests that target key conversion loops and drive enterprise demo bookings.

Requirements

What you’ll need

Strong track record of building things entirely on your own from scratch. You don't wait for a perfectly detailed specification document—you see a gap in our process or tracking and you fix it.
Deep technical mastery of React, Next.js (App Router), TypeScript, and Node.js.
Direct experience building with modern, open-source headless content management systems (ideally Payload CMS, Strapi, or equivalent developer-first tools).
Strong familiarity hosting applications on Vercel and utilizing Edge Middleware, Edge Functions, or CDN-level routing to achieve 0ms-latency personalization.
Advanced knowledge of event tracking architectures using tools like PostHog, Mixpanel, or Segment.
Experience managing data flows into enterprise CRMs (Salesforce) is highly desired.

Benefits

Comp & perks

Opportunity to work at a **high-growth AI startup**, backed by top investors.
**Rapidly growing and backed by top investors including a16z, Y Combinator, and Base10.**
**Ownership & Autonomy** - Take full ownership of projects and ship fast.
**Top-Tier Compensation** - Competitive **salary + equity** in a high-growth startup.
**Comprehensive Benefits** - **Healthcare, dental, vision** coverage.
**Work With the Best** - Join a world-class team of engineers and builders

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

Node.jsEvent Tracking ArchitectureA/B TestingAPI OptimizationData Flow Management

Soft Skills

Problem SolvingSelf-Starter