It depends.

If you have one customer who need it once a week, you add this find-grep-awk script to xinetd and set the PHP page with the couple of fields setting the arguments for the request.

If you have a million of customers per hour, you setup a bunch of terabyte-RAM servers with realtime Scala pipeline, and hire a team to tweak it day and night.

Because that's a two very different problems. And the worst thing to do is to try to solve the problem X with a tools for problem Y.

All those tools are stream processors, why wouldn't the customers see the new data immediately reflected in their account?

Spawn as many servers as you wish, spread your data between them, run your scripts, generate reports, show it to the customers.

Pipe it to a websocket, or curl to some update-account API. Or a mysql/psql/whatever CLI in CSV upload mode so you don't have to worry about injection.

If you want to batch on more than lines, use sponge, or write another few lines of mawk/perl/whatever.

Those are limited examples, and may not always be The Right Way (tm), but there are certainly easy, old, simple ways to take shell pipelines and make the data available quickly in some other store.

That's actually very simple, and there are many ways to do that. If the nature of the task you deal with allows this kind of workflow, it's really worth considering. These days I would use a more proper language like D as a wrapper rather than Bash itself, fore greater flexibility.