Prestashop 1.7→9.1 Full Upgrade -- 3

I need my live store upgraded from Prestashop 1.7.8.6 to the latest 9.1 release without losing a single feature, record, or customization. I rely on a mix of core and third-party modules, custom tweaks, and theme edits that all must keep working exactly as they do now—payment, shipping, catalog, orders, customer accounts, everything.

Scope of work

• Create a safe staging copy of the site and database.

• Perform the version jump to 9.1, handling all backward-compatibility changes.

• Update or replace every installed module and theme so they remain fully functional.

• Migrate and verify all data: products, customers, orders, SEO URLs, multistore settings (if present), translations.

• Thoroughly test front office and back office to confirm that checkout, payment gateways, shipping calculators, stock management, email notifications, and core reports behave exactly as before—or better.

• Fix any conflicts or template overrides that surface after upgrade.

• Push the upgraded store to production with minimal downtime and provide a rollback plan just in case.

What I’m looking for

I will only consider developers who have already completed at least one successful migration from Prestashop 1.7.x to 9.x. Please share a live link or reference and outline the main hurdles you solved (module conflicts, theme rewrites, etc.). Familiarity with overrides, Composer-based installations, and Git version control will be valued.