Senior Web Developer (Growth & Conversion Optimization)

About the Company

Clay's mission is to help organizations turn any growth idea into reality. The company serves thousands of customers—including Anthropic, Notion, Google, and Ramp—by providing unique data, signals, and AI research to power go-to-market strategies. In 2025, Clay raised a $100M Series C backed by Sequoia, CapitalG, and First Round, crossing $100M in revenue with a community of 11,000+ customers, 150+ integration partners, and 125+ agencies.

About the Role

Clay is seeking a Senior Web Developer (Growth & Conversion Optimization) to join their team in the New York City Metropolitan Area. This is a hands-on development role where you'll own the creation of high-converting web experiences in Webflow, from landing pages and conversion funnels to custom integrations and personalization engines. You'll balance rapid iteration with technical excellence, shipping production-grade code that directly impacts conversion metrics and business growth. This is ideal for a developer who loves Webflow, understands conversion optimization, and thrives in a fast-paced, growth-focused environment.

Responsibilities

• Build high-converting web experiences in Webflow, owning landing pages, conversion funnels, and website features from concept through launch, including custom JavaScript for interactive elements and advanced CMS architectures
• Develop technical infrastructure that powers growth by architecting and implementing integrations, APIs, webhooks, and automation connecting web properties to the marketing and sales stack
• Own conversion optimization through code by designing A/B testing frameworks, experimentation infrastructure, and personalization engines that systematically improve conversion rates
• Analyze funnel data to identify bottlenecks, translate insights into technical solutions, and build features that reduce friction and drive measurable improvements in key metrics
• Ship with technical excellence by balancing speed and quality, making strong technical decisions under pressure, and refining based on real performance data
• Collaborate with Marketing, Product, and Growth teams to translate business goals into technical solutions, leading development projects and providing technical guidance to stakeholders
• Push technical boundaries by exploring advanced animations with GSAP, interactive elements with Three.js, and dynamic personalization systems while maintaining performance, accessibility, and conversion focus

Requirements

• 5+ years of professional web development experience, with at least 3 years building conversion-focused websites and landing pages
• Expert-level Webflow development skills, including advanced CMS implementations, custom code integration, and complex builds that push the platform's capabilities
• Strong programming fundamentals in JavaScript/TypeScript, HTML5, and CSS3, with the ability to write clean, maintainable code
• Proven experience with conversion optimization, A/B testing frameworks, and funnel analysis
• Experience building and debugging integrations, APIs, webhooks, and connecting marketing technology stacks
• Strong understanding of web performance, accessibility standards, and best practices
• Ability to balance speed with quality, make technical decisions under pressure, and communicate effectively with non-technical stakeholders

Clay is a growth platform that helps organizations turn growth ideas into reality using unique data, signals, and AI research. The company serves thousands of customers including Anthropic, Notion, Google, and Ramp, and raised a $100M Series C in 2025 at a $5B valuation.