[aasasd]

When improving existing code, only do gradual changes. Don't do rewrites, don't replace existing code with better solutions in one swoop.

This way, you won't be in a situation when the new solution doesn't work in some cases and you already thrown all the code it replaces under the bus. You'll always have a mostly working app.

OTOH, if you introduce an alternative solution, finish migrating to it before beginning improvements in other places in the codebase.