Front End Developer
This job is focused on HTML, CSS, JavaScript, and light backend work. Not design. The lack of “designer” in the title is intentional. Because the job doesn’t require design, deeper skill in the other technologies is implied. You likely have a grasp on some concepts beyond the core technologies, for instance, regression testing or performance.
A synonym might be Front End Engineer. I tend to think of that as a requiring a deeper and more specific skillset, possibly with more narrow focus or at a higher level.
Technology specific job titles may be also be appropriate here, like “JavaScript Developer” or “JavaScript Engineer” for a job where that is primarily what needs to be done. Although, none of the front end technologies live in a bubble so I generally prefer Front End Developer.