[correction: they accidentally called usc1-a a region, but everything mentioned in their outage was a zone. They specifically called it a "deployment zone" not an availability zone, so it sounds like an issue of inexperience with best practices.]
[obligatory disclaimer: I'm a Google employee. I don't have a relationship with Layer]
As an almost-customer of Layer (before their massive price increase), they led me to believe that this was one of the problems they would be solving for me. Nowhere on their website does it say, "We save money by not following best practices, so plan accordingly for occasional outages!"
With that said, we do feel that Google came up in short in their responses to us over the course of the issue. We pay handsomely on a support contract to get off-hours responses and issue escalations. The responses we received were hand-wavy and vague, leaving us without sufficient data to make decisions. We have raised these concerns with our Google representative and will be working with them to tighten our partnership going forward.
We take full responsibility for this event and are working to cover the exposure. Building a system and business with resource constraints and complex distributed technologies is a long game of managing risk and trade-offs. We're human and we make bad calls along the way. We are very sorry and violated our commitments to our customers and their users. The entire Layer engineering team is head down right now working to make it right.