A Compiler-compiler developer designs and builds compiler-compilers, also known as compiler generators or metacompilers. They create tools that generate source code for compilers, interpreters or other translation tools automatically. Their work involves knowledge of programming languages, syntax analysis, and code generation techniques. They design the grammar for the source language, implement semantic actions to produce the target language, and ensure the efficiency and correctness of the generated compiler. Their work is crucial for developing new programming languages or customizing existing ones, and they often work closely with language designers, software developers, and computer scientists.