Node Performance measurement for laymen

node_perf.js

const start = now();

// some task goes here

const end = now();
const time = (end-start).toFixed(4);
const currentList = process.env.PERFLIST;
const list = (currentList) ? JSON.parse(currentList) : [];
list.push(time);
process.env.PERFLIST = JSON.stringify(list);
list.sort();

console.log("current median:", list[Math.ceil(list.length / 2)], "with n:", list.length);