We have big clients like the Government, Telco, and financial sectors.

The solution is scalable.

I would consider Streams to be a cluster rather than cloud focused technology.
This allows me a great amount of control for relatively predictable workloads.

I have yet to come across a use case where the system could not be appropriately sized to accommodate the projected loads while meeting very low latency requirements. That includes some situations where the data volumes are truly enormous and continuous.

There are no scalability issues.

There were no scalability issues.

No issues encountered.