[kortilla]

No, using AWS does not absolve you of that responsibility. The game of paying a vendor to be an engineer is that you have to have strategies to test this kind of stuff.

Slack didn’t know how to handle it, they paid AWS hoping the product did what it said on the tin. They didn’t test for this case and got bit.

They have millions of clients they could have coordinated to load test this stuff by picking some time to disable the cache and fallback to cache if it failed.