Prestashop 1.7→9 Migration

Job ID: 40155895

Budget: €250 – €750 EUR

I need my current PrestaShop 1.7 installation upgraded to the latest 9 .x branch without losing any data or functionality. The shop is large—well over 500 products—and it runs on a custom theme supplemented by several third-party integrations (payment gateways, shipping APIs, marketing add-ons). Everything must survive the transition intact and work seamlessly on the new version.

Key points
• Full database migration (products, customers, orders, CMS pages, SEO-friendly URLs, translations).
• Adapt or rebuild the existing custom theme so it renders perfectly on 9 .x, remains mobile-friendly, and scores well on Core Web Vitals.
• Reconnect and test every external integration we already use, updating or replacing modules when required.
• No data loss or extended downtime; I can allow a short maintenance window but the storefront must remain accessible for most of the process.
• Final deliverable is a fully tested 9 .x store on the live domain plus a complete backup and rollback plan.

Tell me about your experience with large PrestaShop version jumps, especially any projects that involved custom templates and external modules. A concise outline of your migration approach and typical timeframe will help me choose quickly.