In/on prepositions when referring to a front or back-end (computing)

Looking at some examples of the phrases "in the backend" and "on the backend" on Google Books, it seems that anything that runs in the backend (processes, services, etc.) you put in the backend. You use on, for example, when you install something on the backend. When referring to work, you work on the backend, or work is done on the backend.

Some examples I found:

• we tried using an embedded http server in the backend
• since dependence analysis in the backend is usually less accurate than in the frontend
• The processing of a query is carried out entirely in the backend
• Installing DRBD on the backend servers
• Work on the backend translators will involve some extra overhead