Our whole focus is uptime, and I think it's similar to how you use other APIs in your service, how do you deal when you can't reach them?
With that being said, this is something we plan on helping with too. We will have retries to different endpoints (in different geographies), and ways to easily implement it locally. We already offer idempotentcy so that helps.
At some point you're going to have to quantify that and provide enough evidence (of one sort or another) for this claim to be credible. After all, every service under the sun will claim things like 'scalability', 'performance', 'uptime', 'resiliency', whatever. Devil is in the details.
I don't want to nitpick but ... are you really 'focused' on this? You're a startup with limited resources trying to get a product up and running with commercially-viable feature-set. You're not setup for high availability. You just aren't. Proper HA is very hard and as you climb the '9s' in uptime, you introduce huge amount of complexity, cost, planning and manpower - which is something you haven't done and can't do as a startup and, honestly, it isn't worth to do for a Webhook SaaS.
And that's OK! The nice thing about Webhooks is that nobody runs mission-critical workflows with them because there is an implicit expectation of unreliability. This means that for HA/uptime you just need something reasonable. Your service may not survive an AWS outage (or whatever cloud service or datacenter you're deployed in) or a directed DDOS attack, but if your infrastructure can handle traffic spikes and occasional node going down - you're golden.
That's a fair assessment! We are indeed a startup, and definitely have limited resources. What I meant is that this is one of our top concerns that we constantly think about and deploy (our limited) resources on! We are definitely not where we want to be just yet!
With that being said, this is something we plan on helping with too. We will have retries to different endpoints (in different geographies), and ways to easily implement it locally. We already offer idempotentcy so that helps.