I think this is a question of interface vs. implementation.
Python, JavaScript, and other languages which are traditionally considered interpreted but may do (JIT) compilation in their implementation are used as if they were interpreters: to the user, there's no separate compilation step. You run python somefile.py or node somefile.js (or refresh a browser holding a page), and editing the source code causes the next invocation to take those changes immediately. Contrast this with C/C++ and Java where there is definitely an explicit compilation step in nearly all implementations.
The program in this article thus is an implementation of a compiler, but has the interface of an interpreter.
Python, JavaScript, and other languages which are traditionally considered interpreted but may do (JIT) compilation in their implementation are used as if they were interpreters: to the user, there's no separate compilation step. You run python somefile.py or node somefile.js (or refresh a browser holding a page), and editing the source code causes the next invocation to take those changes immediately. Contrast this with C/C++ and Java where there is definitely an explicit compilation step in nearly all implementations.
The program in this article thus is an implementation of a compiler, but has the interface of an interpreter.