Here's the design question that keeps coming back on our SaaS platform: one queue, shared by every customer, sitting between the cloud product and whatever the customer runs on-prem. Is that one queue enough? Scalable enough, reliable enough? I think the answer is yes for a surprisingly long time. What I don't think survives is the dashboard most teams put on top of it.

Start with the plumbing, because the on-prem link is where the decision actually gets made.

There are two ways to get the cloud talking to a customer's data centre. You can have the cloud call in over HTTP, a trigger that hits an endpoint on their side. Or you can put a broker in the middle, Service Bus say, and let the on-prem agent reach out and pull. I'm firmly in the second camp. Customers' firewall teams will say no to inbound holes. They rarely object to an outbound connection on 443 from one agent.…