We don't use Component in production, because it's way too heavy for us. Our web store uses Datomic, PayPal and Stripe, and a few AWS services, and none of these need to be started or stopped.

But we do take a tip or two from stuartsierra's "Reloadable" work flow (which he based Component on), specifically that there should be no global state, and all dependencies should be passed into functions that need them as a parameter.

In our case, we call it `env` since it's the "environment" that a function runs in or can affect, and contains things like the database connection, email service, etc.

Some of these are records which implement a protocol, so that you can have e.g. LiveEmailService in production and MemoryEmailService in development or while running tests.

All in all, I like and have used some of Stuart's ideas, but not necessarily Component itself. There's strong mindshare for it in the Clojure community right now, and it's tempting to look at it as The Solution™ for almost everyone's use-cases because of that. And the ideas it has are good, but that doesn't always mean it's the best solution for each person.