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.
HTTP 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
A single page app relies heavily on JavaScript, it is therefore essential that no resources are missing or syntax errors got in. Furthermore, there may be third party resources that are essential. We can cover this by loading the page in a headless browser (every 15 minutes) automatically and making sure all resources are loaded and no JavaScript errors occur. Furthermore you can monitor the time it takes for the page to actually load. Load time is important for user experience and SEO.
API 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.