JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">
    testing
</div>

JavaScript

var triggerChange = function(event) {
    var addedEl = jQuery(event.target).children('.inner:last');
    addedEl.text('changed ' + addedEl.attr('count'));

    monitorChanges();
};

var monitorChanges = function() {
    //Notice the use of 'one' so the modification I make does not also fire triggerChange
    jQuery('#outer').one('DOMSubtreeModified', triggerChange);
}

var counter = 1;
monitorChanges();

setInterval(function() {
    jQuery('#outer').append('<div class="inner" id="inner' + counter + '" count="' + counter + '">Added ' + counter + '</div>');
    counter++;
}, 2000);