https://www.toptal.com/javascript/asynchronous-javascript-async-await-tutorial but using normal callbacks, that don't catch exceptions, and implicitly handle rejections, using righto, also faster, and optimisable, because it doesn't use try/catch

example.js

const verifyUser = function(username, password, callback){
   const userInfo = righto(dataBase.verifyUser, username, password);
   const rolesInfo = righto(dataBase.getRoles, userInfo);
   const logStatus = righto(dataBase.logAccess, userInfo, righto.after(rolesInfo));
   const result = righto.mate(userInfo, righto.after(logStatus));
   result(callback);
};