Personio’s move from WordPress to a composable frontend
Europe’s all-in-one HR platform for SMBs, Personio, has overhauled its public website. After six years on a monolithic WordPress setup, the company shifted to a composable architecture built on Next.js, Contentful, and Vercel. The result was a major improvement in Core Web Vitals, a more secure hosting environment, and a leaner development workflow.
The old WordPress theme had accumulated significant technical debt. Each new feature added layers of custom code, and while the team could still ship quickly, the site’s performance suffered—especially on mobile, where persistent Cumulative Layout Shift (CLS) issues were a concern. The migration to a headless setup directly targeted these problems.
Performance gains across all domains
Following the relaunch of Personio’s Italian site in 2022, the company saw a sharp increase in traffic. More importantly, their Core Web Vitals scores jumped dramatically. The team reports consistent gains of more than 90% in vitals, with CLS seeing the most significant correction.
These improvements weren’t limited to the new Italian domain. The same positive trends appeared across Personio’s other five websites. On mobile, the Largest Contentful Paint (LCP) score improved by 29%. The shift also gave the team real, data-driven visibility into their vitals, replacing guesswork with a clear optimization strategy.
With the infrastructure managed by Vercel, Personio’s engineers have been able to step back from server maintenance. The platform has operated without interruption since the switch.
“We have full confidence in our site on Vercel. We have roughly 100% uptime, and we’ve never experienced any outages. Deployments to production are very robust, and we haven’t seen any problems. Vercel is quite invisible, which is the best case scenario.”
Peter Rosell, Senior Full Stack Engineer
A stronger security posture for HR data
Given the sensitive nature of HR operations, security was a primary driver in the architecture decision. Next.js supports server-side rendering and static generation, which inherently reduces the attack surface compared to client-rendered applications. This complements Personio’s strict internal security protocols.
Vercel’s hosting layer adds further protection, including automatic HTTPS, end-to-end encryption for data in transit, and DDoS mitigation through the global Edge Network. This setup allows Personio to manage its security framework more closely, moving away from third-party dependencies and tailoring protections to the specific risks of the HR industry—a change that strengthens defenses and builds user trust.
A more efficient developer workflow
The migration also transformed the day-to-day experience for Personio’s development team. Vercel Preview Deployments enable real-time feedback and discussion directly within the preview environment, streamlining the review process.
With a headless architecture, the team can iterate more quickly on new features and updates without being constrained by the monolithic CMS. This agility supports a faster development cycle, allowing Personio to keep pace with the evolving HR tech landscape without sacrificing site performance or stability.
