Sometimes incremental refactoring stops being economical. The frontend may be impossible to extend, the backend may be built on an unsupported framework, or years of workarounds may have made one layer more expensive to maintain than to replace.
That still does not mean the entire product needs a rewrite.
We isolate the layer causing the constraint, define the interfaces it needs to preserve, and rebuild it against the existing system so the transition can happen in controlled stages.


