JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>

JavaScript

var data = {
	"stuff":[
		{"x":0},
		{"y":1, "delete": true},
		{"z":2, "delete": true}
	]
}

Object.keys(data.stuff).forEach(function (key) {
	if (data.stuff[key].delete == true) {
  	data.stuff.splice(key, 1);
  }
});

var postData = JSON.stringify({something:'something', data: data});
console.log(postData);