Frontend, Front‑End, or Front End: Which is Correct?

You can describe the same job as frontend development, front‑end development, or front end development and still be talking about the same work. Unfortunately, that doesn't tell you which version to put in a sentence. A job advertisement, a technical specification, and a colleague's email may each offer a different answer, all with considerable confidence.
My preference is front end for the thing and front‑end when it describes another noun: "I work on the front end" and "I'm a front‑end developer". The closed form, frontend, is an established alternative in technical writing, but I like the grammatical distinction.
The Space and the Hyphen Do Different Jobs
In "the front end needs attention", the phrase names part of a system. It's a noun phrase. In "the front‑end code needs attention", those words work together to describe the code. Hyphenating that compound modifier helps the reader see which words belong together before reaching the noun.
- The front end displays the search results.
- The front‑end application displays the search results.
The meaning is almost identical; the grammatical job changes. The GCC project's spelling guidance makes the same distinction between noun and adjective.
Where "Frontend" Fits
The closed form treats the expression as one technical word: a frontend, a frontend developer, or a frontend build. It keeps the same spelling in each position.
I find the open‑noun, hyphenated‑modifier distinction useful in my own prose, but I wouldn't "correct" a whole project's documentation to match it if that project consistently uses frontend. At that point, the change would mostly record that I had arrived.
I've covered what front‑end development involves separately. The work is the same whichever spelling appears in the job title.
Search for All Three
When searching job boards or other people's documentation, check all three forms. A job board, an internal search tool, and a repository search may not treat spaces and hyphens in the same way. There's no guarantee that a search for your preferred spelling will find the others.
Editing prose and renaming things are different jobs, too. A directory, package, configuration value, or public URL may be referenced by code and by other people. Leave those literal names alone unless you're prepared to deal with the references. My preference for a hyphen isn't a reason to break somebody's build.