Asking the application whether it is answering.
The badge at the top comes from two live checks made by your own browser, not from a reading we saved earlier. The first asks whether anything answers at our address at all. The second asks the application behind it whether it is working and can reach its database. Separating them is the point: it is the difference between our problem and yours.
A green badge is not a promise that every feature works. The section above lists what we do not watch automatically, and any of those can fail while both checks stay green. When we know a specific part is affected, it is named in the log, because that is what tells you whether to keep trading.
Every resolved entry states plainly what happened to your data. Books are not a chat window: if an interruption could have left a document half-written, you are told what to check rather than left to wonder.
We do not publish an uptime percentage yet. Doing so honestly means measuring from outside our own network for a meaningful stretch first. A number we cannot stand behind would be worth less than this page having none.