For simple stuff I've had success keeping an in-memory data structure as the source of truth, and just persisting the whole thing to a file (JSON or otherwise)

For simple stuff I've had success keeping an in-memory data structure as the source of truth, and just persisting the whole thing to a file (JSON or otherwise) via a debounced function. Assuming you only have one process (or at least one main process), you only have to read the file on startup and can be pretty relaxed about your write strategy