Senior Web Developer

About Us
M&C Saatchi Performance is a global digital media agency, connecting brands to people. We deliver business growth for our clients through effective, measurable, and evolving digital media strategies.
About The Role
This role is hands-on development to support different teams across the business, Marketing, SEO/GEO, Creative and CRO, on our site and on client platforms.
What this role will own :
Our website
Site revamps: build and ship the website revamp and the wider redesign, from approved wireframes and copy through to development, QA and launch.
Templates and page builds: location pages, service and sector pages, section pages, blog and article templates, author pages, landing pages and campaign pages.
Performance: Core Web Vitals, page speed, caching and plugin hygiene, with a full mobile responsiveness overhaul.
Integrations: HubSpot forms and tracking, GA4 and Google Tag Manager, job listings via ATS API, and other martech connections.
Maintenance: plugin and core updates, security, staging-to-production workflow, backups, uptime and bug fixes.
CRO, analytics and measurement
Experimentation: implement A/B tests and CRO changes using VWO, Optimizely, Adobe Target or equivalent, and support the testing roadmap.
Front and back end: implement conversion changes across both website and app surfaces.
Tracking implementation: build and QA GA4 and GTM events, data layers, conversion tracking and experiment tracking, working with the CRO and analytics teams.
Debugging: diagnose tracking issues confidently using browser DevTools, GTM Preview, GA4 DebugView and similar.
SEO and GEO implementation
Technical foundations: XML sitemaps, robots.txt (including AI crawler rules for GPTBot, ClaudeBot, PerplexityBot and others), canonical tags, redirects, hreflang where relevant, and llms.txt.
Structured data: Organization, Service, Article and FAQ JSON-LD implemented from specifications supplied by the SEO/GEO team, validated error-free.
On-page execution: metadata, heading structure, internal linking, schema and content-structure changes that make pages readable to search engines and AI answer engines.
Diagnostics: work with the SEO/GEO team on crawl, indexation and log analysis, and fix what the audits surface.
Client delivery
Implementation on client sites: deliver technical SEO/GEO scopes across client platforms, WordPress, Shopify, Webflow, and headless or other CMSs such as Contentful, to agreed acceptance criteria.
Scoping and estimating: size the technical work in audits, pitches and retainers so we quote accurately and commit to realistic timelines.
Documentation: clear handover notes and QA evidence the account and SEO teams can share with clients.
What We're Looking For
Essential :
4–6 years building and maintaining sites in a commercial or agency environment.
Hands-on experience across more than one CMS (WordPress plus Shopify, Webflow or similar).
Strong PHP, HTML, CSS and JavaScript; comfortable with custom themes, page builders and custom post types.
Working knowledge of React and of database management, SQL and MongoDB.
Demonstrable technical SEO implementation experience - schema, canonicals, sitemaps, redirects, Core Web Vitals - and comfort taking direction from GEO/SEO specialists.
Practical tracking and analytics skills: GA4, Google Tag Manager, Google Search Console, and QA of events and data layers.
Experience implementing A/B tests through VWO, Optimizely, Adobe Target or equivalent.
Git-based workflow, staging environments and structured QA before anything goes live.
Comfortable working from design files in Figma.
Able to run several projects and concurrent requests from marketing, SEO and client teams in parallel: strong attention to detail, reliable on deadlines, and honest about what fits in the schedule.
Excellent business-level English communication.
Exposure to GEO, AEO or AI-search optimisation, or genuine curiosity about it.
Desirable
Headless CMS experience (Contentful or similar).
HubSpot CMS, forms or CRM integration experience.
Cloudflare, WP Engine or comparable managed hosting; bot and crawler analytics.
UI/UX sensibility - you can work from a wireframe, collaborate with designers to bring concepts to life, and flag early when something won't hold up in the browser. Figma and Adobe XD experience is a plus.
Prototyping ability, and back-end work for landing page designs, A+ content and interactive media.
Agency background and comfort working with client-facing teams.
How We'll Measure The Role
Development throughput and on-time delivery against the website roadmap.
Site health: Core Web Vitals, mobile usability, uptime, and zero critical technical SEO errors.
Speed from SEO/GEO recommendations to live implementation.
Quality and timeliness of client technical deliverables.
Reduction in external development spend once the transition is complete.
M+C Saatchi Performance as part of M+C Saatchi Group has pledged its commitment to create a company that values difference, with an inclusive culture. As part of this, M+C Saatchi Group continues to be an Equal Opportunity Employer which does not and shall not discriminate, celebrates diversity and bases all hiring and promotion decisions solely on merit, without regard for any personal characteristics.
All employee information is kept confidential according to General Data Protection Regulation (GDPR)
M+C Saatchi Group was founded in 1995 and is now the biggest Independent creative agency group in the World. Founded on one core principle, Brutal Simplicity.

Work arrangement
No