Migrating a Large Adventure Website to a Modern Block-Based System

Ultimate France had a large, content-rich site built on a legacy Genesis framework with hundreds of pages and deeply embedded ACF data. The project required a complete theme migration and redesign while preserving every field, meta key, and piece of structured content across the entire site.
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Legacy Genesis templates fully migrated to GeneratePress

ACF data and meta keys preserved across hundreds of pages

Performance improvements via Perfmatters configuration

Pattern library delivered for independent page creation

About the Project

Ultimate France is an information-rich destination website covering outdoor adventure activities across France, including surfing, skiing, and mountain biking. The site contained hundreds of location and destination pages, each relying on custom field data built up over years.

The existing Genesis-based theme had become difficult to maintain and the design needed to be modernised. The project combined a full theme migration with a redesign, all without disrupting the existing content structure.

Complex TemplatesCustom ThemeDesign LibraryEditorial UX

The Challenge

The site’s scale made this a high-risk project. Four to five core templates were applied across hundreds of pages, each tightly coupled to ACF field groups. Any change to the meta key structure would have broken content across the entire site.

The migration had to be handled methodically. The design could only be updated after the data integrity of every template was confirmed. Speed and visual changes were secondary to getting the structural work right first.

  • Legacy Genesis theme applied across hundreds of individual pages
  • Each page relying on ACF fields with established meta keys
  • Template logic required full analysis before rebuilding could begin
  • Data integrity could not be compromised during the migration
  • Modernised design required without disrupting existing content

The Approach

The project followed a strict sequence: analyse first, migrate second, then redesign. No visual work started until the template and data structure was fully mapped and confirmed.

1

Template and Data Analysis

Every existing Genesis template was reviewed and mapped. All custom fields and meta keys were documented before any development work began. This created a clear reference for rebuilding each template without data loss.

2

Block-Based Template Reconstruction

Each template was rebuilt using GeneratePress and GenerateBlocks, with ACF fields remapped exactly to their original meta keys. The new templates became fully visual and significantly easier to update, without any loss of the existing content relationships.

3

Performance Optimisation

With the new templates in place, Perfmatters was installed and configured. HTML structure was improved, unnecessary overhead from the legacy system was removed, and load times were measured before and after to confirm the gains.

4

Pattern Library Creation

A reusable pattern library was built and handed over to the client. This gave them the ability to create new destination pages independently by inserting pre-built sections and filling in text and images, without needing development support each time.

The Outcome

A modern system with every existing data point intact

  • All Genesis templates successfully migrated to GeneratePress and GenerateBlocks
  • ACF data and meta keys preserved across hundreds of pages
  • Improved frontend load speed after Perfmatters configuration
  • Modern, consistent visual design applied across all template types
  • Pattern library delivered, enabling independent page creation
  • Client fully equipped to expand the site without development dependency

The migration removed years of technical constraint while keeping the content infrastructure the site depended on. The result is a maintainable, scalable system that supports long-term content growth without ongoing development overhead.