With single page apps, checking whether the page is served by the server is not really sufficient to ensure a customer sees anything. However, with a little extra effort you can still monitor these pages effectively. I recommend three different angles to your monitoring strategy: a simple HTTP check, a full browser check and an API check.
Although not much can go wrong with a static page, it’s still important to monitor it. HTTP status monitoring is the quickest way to know about configuration issues with e.g. SSL certificates, DNS and your web server.
Full browser check
To make sure a single page app does not only load, but can also show useful information quickly, it is important to also monitor the API that it calls. We strongly recommend monitoring not just a static /ping endpoint but an actual major endpoint that requires a logged in user. (assuming you require users to log in). An example could be a listing that is part of your home/main screen.