What does this have to do with frontend work? Major version updates are common across any part of the stack. Just off the top of my head, SQLAlchemy has a seven step migration process[1] from 1.4 to 2.0, and it's absolutely not the kind of thing you could pull off in a few days if your code base has grown past a certain size.

[1]: https://docs.sqlalchemy.org/en/20/changelog/migration_20.htm...