Sr. Optimizely Developer

Horizontal Talent is hiring a Senior Optimizely Developer in Denver, CO for onsite work. In this role, you will help teams launch scalable CMS capabilities and sophisticated Optimizely experiments, including personalized web experiences for targeted B2B audiences, with support from AI-assisted development tools.

What you’ll do

• Build and maintain reusable components, page templates, and content models in Optimizely CMS to support efficient marketing page launches.
• Design CMS architecture that prioritizes scalability, security, and performance, including Core Web Vitals optimization.
• Develop and support integrations between Optimizely CMS and enterprise platforms including Salesforce, Marketo, Adobe Commerce, plus internal systems.
• Create, deploy, and maintain advanced A/B, split, and multivariate tests using Optimizely Web Experimentation, including custom DOM manipulation and dynamic content changes.
• Implement personalized web experiences for targeted B2B audiences and account-based marketing campaigns.
• Support server-side testing and feature flagging when frontend testing is not the best fit.
• Run thorough cross-browser and cross-device testing to reduce flicker and layout shift and maintain consistent user experiences.
• Define and document best practices, technical standards, and governance guidelines for Optimizely-related work.
• Collaborate with CRO, product, and design teams to evaluate ideas, prototype solutions, and translate designs into polished digital experiences.
• Use AI-assisted development tools to accelerate coding, debugging, testing, and experimentation workflows.

Key requirements

• 5+ years of full-stack web development experience.
• 3+ years of hands-on experience working within the Optimizely ecosystem.
• Strong backend development skills with C# and .NET Core/MVC, especially in Optimizely CMS environments.
• Advanced frontend experience with HTML5, CSS3/SASS, and JavaScript, including Vanilla JS, ES6+, jQuery, React, or Vue.
• Deep understanding of Optimizely concepts such as Project JS, visual tags, audience targeting, anti-flicker approaches, and caching behavior.
• Experience supporting complex B2B websites, including lead generation and gated content workflows.
• Strong Git knowledge and familiarity with modern CI/CD workflows such as Azure DevOps or GitHub Actions.
• Ability to work independently while collaborating effectively across cross-functional teams.
• A proactive, solution-oriented approach with focus on speed, quality, and continuous improvement.

Technologies you’ll work with

• Optimizely CMS, Optimizely Web Experimentation
• Salesforce, Marketo, Adobe Commerce
• Core Web Vitals, A/B testing, split testing, multivariate testing
• C#, .NET Core, MVC
• HTML5, CSS3, SASS, JavaScript, Vanilla JS, ES6+, jQuery, React, Vue
• Git, Azure DevOps, GitHub Actions
• Project JS, visual tags

Preferred skills

• Active Optimizely Developer certification in CMS or Web Experimentation.
• Experience supporting server-side experimentation and feature flagging initiatives.
• Familiarity with UX/UI collaboration and translating wireframes or Figma designs into interactive experiences.
• Comfort using AI tools such as GitHub Copilot or ChatGPT to improve development efficiency.
• Experience working in remote-first environments and collaborating across multiple locations.