Senior Optimizely Developer — Scale CMS, Experiments & AI

Horizontal Talent; Philadelphia (Philadelphia County); On-site; USD 79,000 - 130,000; Full time

Benefits offered by this job

Medical insurance

Dental insurance

Vision insurance

Retirement plan

Job summary

Horizontal Talent seeks a Senior Optimizely Developer to build scalable CMS solutions, run sophisticated experiments, and leverage AI-assisted tools to accelerate development. The role focuses on integrating Optimizely with enterprise platforms, designing robust CMS architectures, and delivering high-quality digital experiences for B2B audiences.

You will collaborate with CRO, product, and design teams to prototype solutions and translate designs into polished experiences using advanced testing

Qualifications

• 5+ years of full-stack web development experience.
• 3+ years in Optimizely ecosystem.
• Strong backend development with C# and .NET Core/MVC in Optimizely CMS.
• Advanced frontend experience with HTML5, CSS3/SASS, and JavaScript (Vanilla, ES6+, React, or Vue).
• Deep understanding of Optimizely concepts: Project JS, visual tags, audiences, anti-flicker, caching.
• Experience building for complex B2B sites, lead gen, gated content workflows.
• Strong Git knowledge and CI/CD familiarity (Azure DevOps or GitHub Actions).
• Independent worker who collaborates well with CRO, product, and design teams.

Responsibilities

• Build and maintain reusable components, templates, and content models in Optimizely CMS.
• Design scalable CMS architecture with performance and Core Web Vitals in mind.
• Develop integrations between Optimizely CMS and Salesforce, Marketo, Adobe Commerce, and internal systems.
• Create advanced A/B, split, and multivariate tests in Optimizely Web Experimentation.
• Implement personalized web experiences for targeted B2B audiences and ABM campaigns.
• Collaborate on server-side testing and feature flagging when frontend testing isn’t ideal.
• Perform cross-browser and cross-device testing to ensure stable UX.
• Define and document best practices and governance for Optimizely work.
• Work with CRO, product, and design to translate wireframes into live experiences.
• Leverage AI-assisted tools to speed up coding, debugging, testing, and experiments.

Skills

Full-stack development

Optimizely CMS

C# / .NET

HTML CSS JS

Project JS

Git CI/CD

Cross-functional teamwork

AI tools

Tools

Azure DevOps

GitHub Actions

Salesforce

Marketo

Job description

Horizontal Talent seeks a Senior Optimizely Developer to build scalable CMS solutions, run sophisticated experiments, and leverage AI-assisted tools to accelerate development. The role focuses on integrating Optimizely with enterprise platforms, designing robust CMS architectures, and delivering high-quality digital experiences for B2B audiences.

You will collaborate with CRO, product, and design teams to prototype solutions and translate designs into polished experiences using advanced testing