&gt; Once you scratch a little bit the surface, you will see the extraordinary power of its persistent data structures.<p>I&#x27;ve heard this repeatedly, yet in the examples I&#x27;ve read (for web servers and for web ui work with cljs), they&#x27;re using atoms with `swap!` to provide &quot;current state&quot;.<p>Could you provide an example of using persistent data structures in a web app?  Or am I mis-understanding?