Recommendation for performance and scale

I am getting close to being feature complete.
My App makes use of a fairly extensive use of Cloud functions, React app hooks, Search functionality, Smart Contract interactions, Live Queries to be reactive and so on.

As I am transitioning my focus toward deploying this to prod, I wonder what would be the best approach to scale. I know it is hard to know before hitting the fan but do you have recommendations based on your experience on this? I figured having multiple teams leveraging those tools should allow to aggregate experience.
Can Cloud functions scale to 1000s of simultaneous users (or more) if many components make calls?
How many live queries can I reasonably expect to work on a single page at scale?
What are the recommendations to reduce costs?
I know it is a non-exhaustive list but I am unclear how to approach this problem.


for cloud functions, it could depend on how complex they are, they will execute faster if there is less code to execute

yes. I can try to keep them as simple as possible. Right now I use CloudFunction because the aggregate/pipeline function is only available through CloudFunction (is that right?) or for functions that require access to the User table.

I am debating whether running search on the client or in a cloud function is better. I need to have a string search capability for my App. I am betting Cloud would be better for this but I am wondering if you have done performance/benchmarking to recommend one of the other?

I don’t have benchmarks, there is also the option to not call those function too often, in case that you have too many users