So I wanted to paste this in the existing DSA Q & A thread but it would be out of context since this is more geared towards a design problem.

So you've been hired by company XYZ hosting service on xyz.com and this is the challenge. Their customers want to attach their own domain names since it's a multitenant app. So instead of going to xyz.com as a premium customer, I can go to my own domain name e.g. abc.de or better still customer1.abc.de and I should still access the service. Company XYZ is already running a microservice, frontend and backend, both exposed to the internet. With your decision, they are willing to alter the infrastructure to a greater degree.

Your solution should try as much to keep costs [Big O and monetary] within a minimal limit when deployed and progressively should be scalable to an infinite amount of customers' domains.

Bonus points if you show a solution that doesn't work, or works but is not scalable, or works but is very expensive.
There's a 90% chance you will mostly come across this problem in everyday life.

Spambot, kindly spare this post.

I need to learn faster and work harder, Everything you wrote up there looks like spanish to me ffs.

Sulele04:
I need to learn faster and work harder, Everything you wrote up there looks like spanish to me ffs.

Give it your best shot, it doesn't matter if you feel you're wrong. How would you know your answer is wrong unless you try first, right?

This can be easily solved by routing/redirects on the ABC.com to xyz ip.. if abc.com is hosting something important already all it can do is create a subdomain AAA.abc.com and point it to the ip of xyz.com.
U can easily use Amazon ec2 to host xyz, get an elastic Ip and your client domain can be configured to point to that domain.

samueltoski:
This can be easily solved by routing/redirects on the ABC.com to xyz ip.. if abc.com is hosting something important already all it can do is create a subdomain AAA.abc.com and point it to the ip of xyz.com.
U can easily use Amazon ec2 to host xyz, get an elastic Ip and your client domain can be configured to point to that domain.

I'd have given a similar answer to this honestly or using domain aliases, configuring your dns to point to a wildcard subdomain. *.example.com

You might still need to do some server configuration so the subdomains can point to the appropriate document root.

Probably wrong but like he said, it doesn't really matter.