So, I asked Pipedrive to provide a complete list of updates that happened in the time the system was down.
That’s all fine and I’m looking through the csv files I got 
But what do we do next time this happens? It was only because of a very obvious missing update we even noticed this problem existed.
A “webhook log API endpoint” would be very usefull, as suggested here:
If we can’t rely on all updates getting through webhooks, we need to rethink all cases where we compare the “current” vs “previous” state. The whole “previous” chunk of the update could even be removed.
I know it’s a shitty situation that shouldn’t happen, but a lot of our system is designed around updates coming through so we can react accordingly.
Thanks for letting me vent It’s just getting a bit frustrating spending time building workarounds around the Pipedrive system.
You all have a nice day 