Last time I worked with XSLT was in 2014, redesigning a major Brazilian airline reservation and ticketing system. At the time their passenger service system (Navitaire New Skies [1]) had already switched their white label front-end app from a home grown XSLT web framework to ASP .NET MVC 5, but the company I was working for wasn't particularly interested in paying the (higher) fee for using the "new" front-end framework.

[1] https://www.navitaire.com/new-skies-reservation-system