[watwut]

Quoting parent: "plus internationalisation, plus thorough automated tests and deployment. They seemed to be really happy with it."

Sounds like success.

There is a reason why stakeholder would like the change despite large cost - if the old system was unstable and source of stress and fires for the stakeholders, they will go for more expensive option.

Kind of like after you had a car that needed to be fixed every few weeks, you will go for more expensive higher quality one next time.