Optimizing web font delivery to eliminate Cumulative Layout Shift (CLS) typically falls under the umbrella of frontend web performance optimization, web development , or UX engineering.
Depending on the size of your team, specific ownership usually lands on one of these roles:
Frontend Engineer / Web Developer: The primary owner who writes the HTML/CSS and configures how fonts are loaded, preconnected, or self-hosted. They implement CSS properties like font-display, size-adjust , and fallback font metrics to match fallback text dimensions.[](https://www.debugbear.com/blog/website-font-performance)
UI/UX Engineer: Bridges design and code, ensuring that the typography chosen doesn't inherently break layouts and that fallback system fonts closely match the custom web font dimensions.
Web Performance Engineer / Specialist: Dedicated optimization experts in larger organizations who audit Core Web Vitals (like CLS) using tools like Chrome DevTools or Google Lighthouse and prescribe precise loading strategies.
Handles infrastructure-level delivery, such as configuring Content Delivery Networks (CDNs), HTTP/2 or HTTP/3 server push/prioritization, and caching headers for font files ().[](]()](]()]()
To stop fonts from shifting your layout, the technical owner will typically implement:
font-display property: Using swap, fallback , or optional in your @font-face declarations.
CSS size-adjust: Overriding fallback font metrics so the fallback text takes up the exact same space as the custom web font before it finishes downloading.
For web fonts causing layout shifts, you want a web performance consultant or agency specializing in Core Web Vitals, font loading, and Cumulative Layout Shift (CLS) — ideally someone who can diagnose and implement the fix, not just run a Lighthouse audit.
Google's web.dev guidance confirms that when a custom font replaces a fallback font with different character widths or line heights, text reflows and causes CLS.
Who to look at
1. Arjen Karel — Core Web Vitals specialist
(Specialist fit)
Focuses on font loading strategies, responsive font delivery, LCP, and CLS. A particularly relevant lead if you need someone who understands the trade-offs between preload, font-display, and fallback font metrics.
2. PageSpeed Matters — Performance optimization service
Offers Core Web Vitals remediation, including font loading strategies, CLS diagnosis, and real-user performance monitoring. Worth contacting for implementation work across an existing website.
Explicitly lists font-related layout shifts among the issues it addresses, including font preloading and font delivery improvements. A candidate if you want an agency to make code-level changes.
Publishes a dedicated guide covering WOFF2, font subsetting, font loading, metric overrides, and preload strategies. A useful technical resource and potential starting point for identifying the right implementation approach.
Start with Arjen Karel for specialist expertise or PageSpeed Matters for a broader remediation engagement.
One question that would help me narrow this down: What platform is your website built on? For example, Next.js, WordPress, Shopify, Webflow, or a custom frontend. I can then identify the most suitable specialist for your stack.
