Senior Software Engineer, Media Platform (JavaScript)

Squarespace is looking for a Senior Frontend Engineer (with some experience in fullstack engineering) to join the Media Platform team within our Building Blocks Platform Engineering organization. The Media Platform powers how media assets—images, videos, audio, files, and fonts —are uploaded, processed, stored, and delivered across all Squarespace products. This team's mission is to deliver a scalable, performant, reliable, and secure media experience for internal developers and end users alike.

As a Senior Software Engineer on the Media Platform team, you will shape the architecture and evolution of this critical layer, in collaboration with product and infrastructure teams. This is a unique opportunity to work with infrastructure and product teams to drive performance improvements that directly impact user experience.

You will report to the Engineering Manager of Media Platform in our NYC office. This is a hybrid work opportunity with three days in the office.

• Lead frontend development across media-serving interfaces and tools using React, JavaScript, CSS, and HTML.
• Integrate media APIs and optimize asset pipelines, especially around image, video, and font rendering.
• Improve rendering performance across customer-facing surfaces, applying best practices for lazy loading, progressive rendering, responsive design, and CDN-based optimization strategies.
• Work with designers, infra engineers, and product teams to build performant, user-friendly media workflows.
• Contribute to long-term architectural decisions, including media caching strategies, compression techniques, and CDN configurations.
• Provide mentorship, conduct code reviews, and shape frontend and performance standards for the team.

• 6+ years of professional experience in frontend development in Javascript with 2+ years of experience in backend development in any language.
• Proficiency with React, JavaScript, HTML, and CSS, including modern frontend tooling (Webpack, Babel, ESLint).
• Experience with web performance techniques, including rendering path optimizations, critical CSS, TTI, LCP, CLS, and other Core Web Vitals.
• Prior experience improving media-related performance (e.g., optimizing large images, video streaming, font delivery, CDN strategies).
• Experience working with or building internal tooling for media workflows, such as uploaders, preview tools, media transformation pipelines.

• A choice between medical plans with an option for 100% covered premiums
• Fertility and adoption benefits
• Access to supplemental insurance plans for additional coverage
• Headspace mindfulness app subscription
• Global Employee Assistance Program
• Retirement benefits with employer match
• Flexible paid time off
• 20 weeks for parental leave and up to 12 weeks to care for an ill family member
• Pretax commuter benefit
• Education reimbursement
• Employee donation match to community organizations
• 8 Global Employee Resource Groups (ERGs)
• Dog-friendly workplace
• Free lunch and snacks
• Private rooftop
• Hack week twice per year

The base salary for this position will vary based on job-related criteria including relevant skills, experience, and location, among other factors.

In addition to the cash compensation above (which includes base salary and, where applicable for eligible roles, may include on-target commissions or overtime pay), Squarespace employees are eligible to be granted an option to purchase our common stock.

Squarespace is a design-driven platform helping entrepreneurs build brands and businesses online. We empower millions of customers in more than 200 countries and territories with all the tools they need to create an online presence, build an audience, monetize, and scale their business. Our suite of products range from websites, domains, ecommerce, and marketing tools, as well as tools for scheduling with Acuity and creating and managing social media presence with Bio Sites and Unfold. Our team of more than 1,500 is headquartered in bustling New York City, with offices in Dublin, Ireland, Aveiro, Portugal, and coworking spaces in the UK, Netherlands, and Australia. For more information about our company culture, visit https://www.squarespace.com/about/careers.

Today, more than a million people around the globe use Squarespace to share different perspectives and experiences with the world. Not only do we embrace and celebrate the diversity of our customers, but we also work toward the same in our employees. At Squarespace, we are committed to equal employment opportunity regardless of race, color, ethnicity, ancestry, religion, national origin, gender, sex, gender identity or expression, sexual orientation, age, citizenship, marital or parental status, disability, veteran status, or other class protected by applicable law. We are proud to be an equal opportunity workplace.

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