There are some general tricks that are language-agnostic, like allocating a huge "buffer" object when the app starts, the size of which is some significant portion of the memory you allow the process to use, which always has a reference, then storing references to other objects you need in that big object. In other words, circumvent the garbage collector.

Of course, this has its own issues, but I've seen it done in e.g. Go before. Its likely you'll inevitably end up with leaks, but if your service is fungible and can tolerate restarts, basically what you're doing is moving the "GC Pause" to be a "Container Restart" pause, which may be slower, but would happen less often. Some languages have ways to manually call the GC (Node is not one of them, afaik).