The request
“We're looking to update the theme to a newer version. We also use a translation app and the currency keeps switching back to sterling at the last checkout step.”
Two problems, one project. The theme was behind and the currency conversion wasn't holding through checkout.
The approach
We updated the theme on a duplicate, carried the brand's customizations forward, and resolved the currency behavior so the customer's selected currency holds through to payment. Both were tested together before publish.
What we shipped
Theme updated to current version
Customizations carried forward
Currency selection holds through checkout
Tested across the brand's markets