Dealing with boilerplate code
Examples in codeCircle have too much boilerplate code, which users considered noisy, difficult to read and to navigate. JSFiddle deals with it using a leaner approach which separates HTML and JS.
Recommendation: In the case of CodeCircle, which doesn't separate code, it means isolating functionalities in code sections clearly delimitating them with large comment blocks (e.g., "data acquisition" block, "setting up ML" block, "UI event handling" block, "UI logic" block, "data storage and retrieval" block, etc.)