When to rewrite a code base from scratch

Question

I think back to Joel Spolsky\'s article about never rewriting code from scratch. To sum up his argument: The code doesn\'t get rusty, and while it may not look pretty afte

Answer 1

I would rather do things bit by bit, e.g., create a back-end to the database with a data model as you work in those areas (i.e., user login first, then user management, and so on), and tweak the existing front-end to use the new back-end (interface driven, so you can also add tests). This will keep the existing code with possible undocumented tweaks and behaviours that you wouldn't replicate by developing again from scratch, whilst adding in some separation of concerns.

After a while you will have migrated some 60% of the code base to use the new back-ends without the work being an official project, just maintenance, so you will be in a better position to argue for development time to do the other 40%, and once that is done the existing front-end classes will be vastly reduced in size and complexity. Once it is fully migrated, you will be able to reuse the new back-end model and controller components if you ever get the time to implement a new view.