Acturis is a large multisite with subsites serving different countries and languages – including France, Canada and Germany as well as the UK and USA.
When they underwent rebranding, they also needed to streamline their services by moving to new hosting. This had to be a staged migration to accommodate timescales for different teams. The subsites were updated and launched one at a time.
This meant a staged updating of DNS, and keeping track of which subsite was the live version across multiple servers! An exercise in attention to detail, to make sure there was no downtime or loss of transactional data.
I worked on this migration (and subsequent WordPress maintenance) as a developer for Wholegrain Digital.