Should the code be stored in the database or an analogue of the Strategy pattern?

Question

Design patterns

What to do if there are certain algorithms (download, process, notify, for example) - like examples, parsing, downloading files via http / ftp, via a direct link, via a password in the parameters, with authorization, etc. - and in them all the steps are the same, except for one (different markup of the file during parsing or a different sequence of actions for downloading files). And there can be a lot of entities (sites, download sources) and they are constantly being added.
How often is design applied at all when pieces of code are stored somewhere separately? And is it a huge crutch? Of the examples, I only remember a story from some book about rails, where the validation code was stored in the database on some large e-commerce portal.
And what is the best solution in such situations - writing your own DSL?