I have the below code snippet in NodeJS.

console.log("START");

setImmediate(() => {
  console.log("setImmediate 1");
});

setTimeout(() => {
  console.log("setTimeout 1");
}, 0);

Promise.resolve("hello").then((obj) => console.log("Promise 1"));

console.log("END");

Most of the time the output I get is as given below:

START
END
Promise 1
setTimeout 1
setImmediate 1

However in some cases I do get the below output:

START
END
Promise 1
setImmediate 1
setTimeout 1

Basically the execution order of the setTimeout and setImmediate are changing.
Can someone please make me understand the logic behind this?