Senior Frontend Engineer, Marketing Website (Astro)

Location: Hybrid from the London, UK office; remote work may be accommodated elsewhere in Europe subject to compliance and right-to-work checks.

Company

Synthesia develops an AI video platform for business and enterprise skill development, used by over 90% of the Fortune 100.

What you will do

• Build, scale, and evolve the marketing website’s Astro section library, Sanity schemas, and design tokens.
• Own the content model and design schemas that enable editors and AI agents to create correct pages by construction.
• Implement Figma component specifications as responsive, accessible production interfaces across mobile, tablet, and desktop.
• Extend the platform for AI-assisted development and maintain SEO integrity across canonicals, sitemaps, structured data, redirects, and launches.
• Raise engineering standards through code review, reusable patterns, targeted tests, and technical direction for the next 6–12 months.
• Maintain localisation across nine locales and its translation pipeline for a global audience.

Requirements

• At least 5 years of software engineering experience, including 3 years at senior level, building frontend systems for content-driven or marketing platforms.
• Hands-on ownership of content models in Sanity, including schema design, references versus embedded objects, runtime variants, GROQ, and Portable Text.
• Expert HTML, CSS, and TypeScript skills, with strong component API design and shared-library developer experience.
• End-to-end engineering ability across frontend and server-side systems, including SSR, serverless and edge runtimes, API routes, SQL databases, secrets, and CI.
• Experience taking features from schema to component to serving route, including debugging production-only issues.
• Strong understanding of responsive design, cross-browser compatibility, and web performance; comfortable building to WCAG 2.2 AA.
• Accountability for performance, SEO, analytics events, and conversion metrics.
• Strong craft, attention to detail, communication, collaboration, reasoning, code review, and mentoring skills.

Nice to have

• Experience with a large SaaS marketing website operating at significant traffic and business stakes.
• Astro or another islands/static-site framework; Cloudflare Workers or another edge/serverless platform; and AWS Lambda.
• Tailwind CSS v4 and token-based design systems.
• Experience or strong interest in making component libraries and content models consumable by AI agents.
• Strong design sensibility and experience improving design decisions.
• Localisation and internationalisation at scale, plus analytics and tag management including dataLayer events, server-side tagging, and attribution.

Culture & Benefits

• Full-time role within the Marketing / Website department.
• Hybrid work is preferred from the London office; remote work may be possible elsewhere in Europe subject to compliance and right-to-work checks.
• Work on a platform visited by millions of people monthly and used as a key customer acquisition channel.