RunKit + npm: jazz.js

const jj = require("jazz.js") // fresh script jj.script([ a => doProcess1(a), b => doProcess2(b), c => doProcess3(c), d => doProcess4(d), e => doProcess5(e), ]); // is real equivalend to: dProcess1(function(){ dProcess2(function(){ dProcess3(function(){ dProcess4(function(){ dProcess5(function(){ }); }); }); }); });