Why did my old question suddenly disappear after it got downvoted once?

Question

A couple of days ago I suddenly got down voted on two of my old questions within seconds (which I thought was a little suspicious, since neither had had any activity for a long time, but it was just -4 reputation, so no big deal), then today I noticed another one of them has suddenly disappeared. It was one with low views and no good answers, as apparently trying to use Play Framework and DB2 isn't a very popular choice among the SO community.

Nevertheless, since it was my own question, should I have gotten some sort of a note about it being suddenly deleted? If it was somehow unfitting the SO format, I'd like to know what went wrong to be able to phrase things better the next time I run into similar problems.

Or is it just a case of the daily script deleting it, after it got voted down from 1 to 0 (low views, over a year old, etc.)?

Don't really mind the question being gone, as the problem behind it has disappeared, would just like to understand the system.

Answer 1

Your question became eligible for the Roomba. As can be seen from that link there are several criteria to be matched before a question gets deleted.

As you noticed, a down vote can make your question eligible for deletion but also a comment clean-up can cause a similar outcome or a down vote or deletion of an answer.

You can use the Roomba Forecaster to find out if or when a question will fall victim to the roomba. Based on that info you can help its faith a bit, whatever you believe its faith should be.