To prevent potential conflicts between parallel experiences, you can make use of the prioritization mechanism of Unless.
With Unless, you can segment your customers into audiences. Just like in real life, a website visitor may be part of several audiences at the same time. This means that multiple experiences may fire at the same time. The good news is that every single website visitor sees their own, unique version of your website - tailored to them specifically. Without a lot of work, and even if you have a lot of traffic.
There is a catch, though. In theory, experiences may be trying to adapt the same element on the same page. To prevent such conflicts, Unless introduced a prioritization method for experiences, in which only the most important experience can change an element.
It works like this. When creating an experience on a web page, this experience must be prioritized with respect to the other experience(s) on that page. You can do that by dragging the experience to the right position in a list that contains all experiences on that page. If, by any chance, experiences would conflict, the higher ranked experience will execute first and lock the changed element. This element can then no longer be changed by any lower ranked experience.
For the techies: before an experience is applied to any element, we will look for locked child elements or locked parent elements. If we find either one of those, we will not apply the experience.
You can find this feature in the detail view of each experience, as highligheted in the screenshot below.
Keep in mind: multi-page experiences always have a lower priority than experiences that execute on one page only. The reason is that they are by definition less specific.