[m1el]

From my observations: cold start, ease of patching. If you're running a lot of different JS code or restarting the code frequently, it's faster than node. Where it's useful: fuzzing. If you have a library/codebase you want to fuzz, you need to restart the code from a snapshot, and other engines seem to do it slower. It's also really easy to patch the code, because of the codebase size. If you need to trace/observe some behavior, just do it.