If every server, file and line of code in a service is replaced over ten years, is it still the same service? Philosophers have been asking the planks-and-ship version for centuries.

The question is not just academic. Identity matters for contracts, brands and even personal data. Bring your best argument to the forum thread.

Why it is in the vault: it is the kind of find worth coming back to. Add sources, corrections and related links in the discussion thread.