I recently joined a company and inherited an AWS setup that uses a single CloudFront distribution with 3 alternate domain names and 3 origins.

Set up looks like this:

2 origins are S3 buckets hosting frontend applications

1 origin is an Application Load Balancer connected to backend apps running on EC2

Different domains point to the same CloudFront distribution

Example:

app1.company.com → S3 frontend

app2.company.com → S3 frontend

api.company.com → ALB backend

In my previous company, we used separate CloudFront distributions for different applications/origins, so this shared setup is new to me.

I wanted to ask experienced AWS / DevOps engineers:

Is this a common production setup?

What are the pros and cons of using one shared CloudFront distribution?

At what scale do companies usually split into separate distributions?

Would you keep this architecture or redesign it?

Looking for real-world experiences and best practices.