orthography - Full-stack vs Full Stack, Back-end vs Back end, Front-end vs Front end

Software Developers use the dash interchangeably for these terms.

Front-end meaning one works on the "Front End" of an application (e.g. HTML), Back-end meaning one works on the "Back End" of an application (e.g. PHP), and Full-stack meaning all of the above.

Is there a proper spelling of these terms? Or does it matter?

Answer

The usual principle is that a attributive adjective gets hyphenated (it was a hard-fought victory), but a predicative adjective does not (the victory was hard fought).

The punctuation usually follows the syllabic stress. Note that in hard-fought victory, there is only one stressed syllable in hard-fought, whereas in the victory was hard fought, there are two stressed syllables in hard fought.

So you'd have front-end system.

The noun phrase front end shouldn't be hyphenated: both words are stressed.