Performance consideration for search cluster

Elastic Stack Elasticsearch
1

Hello,
We have a large catalogue of about 120,000,000 documents and we want to release these for general public consumption from different devices.

What kind of things would I need to consider when designing the cluster purely for search at these volumes?

Would reverse proxy have any performance implications, if this is added?

Any advise is much appreciated

2

Depending on the load, I'd may be increase the number of replicas and may be the number of nodes to be able to deal with the search requests.

Having a coordinator node in front of the cluster would also help may be.

BTW did you look at cloud.elastic.co for this?