Why do some new questions show up as 10-15mins old?

Question

I have noticed that sometimes new questions don't show up until they are 5-10mins old. Some of them even have answers that are not much younger.

I have been running a few experiments:

With a partner we use two different computers on the same LAN.
We used separate accounts.
We refreshed the page using the "new" navigation button until a new question showed up in the feed.

On more than one occasion, one of us was able to see a new question for approximatively (5-10) mins. before the other.

Can someone please explain the delay?

Per CRT:

Link https://softwareengineering.stackexchange.com/questions?sort=newest

Question: Fixing a bug that has never caused a problem until now

On that specific question the first answer was not post yet when I clicked on the question. After I answered, I noticed that the question was answered and the time on the answer read 10 mins ago. Then I noticed that the question was 14mins old. I am positive that it did not take me 10-14 mins to write two sentences. That is what spawned the investigation.

Answer 1

It's almost certainly a ubiquitous caching strategy.

Listings are retrieved from the database say once a minute and cached for that duration. All the requests in-between are served that cache version. This way it lowers the strain on the servers.

However 15 minutes for that active site is way too much. Most likely explanation would be they were tweaking something which affected this cache update. You just hit this time.