Hello,
First of all thanks for this awesome Product 
Is it currently possible to manage alert rules for more than one Project?
Or alternatively, set a default alert rule?
We use the Microsoft Teams Integration and it is quite annoying to create a new rule
for every new project.
This has been discussed here previously, but I think it would deserve a revisit.
Greetings,
Patrick
Hello,
No. You will have to do it through the API. Make one alert rule from the web and then use my script from the link and you will be done in a jiffy.
Using a script like this feels very cumbersome, I was considering this option but I was hoping for something built into sentry.
See this post as feature request
If you need to add a alert to more than a few project it will take much longer time to do, if not through the API 
Not possible today unfortunately, but we’ve heard asks for this and wanna build it in the future.