As of 9AM PT today (11/20/2019) we are seeing a lot of 504 Gateway time-out errors when querying the /email/public/v1/campaigns endpoint. Every few requests are taking a long time to respond and some are eventually timing out.
The API is becoming very slow after only a few requests, and we were not seeing this issue prior to 9AM PT - 11/20/2019. I cannot see any reported outages on http://status.hubspot.com/, are you experiencing any issues that could be causing this?
That's good to know! Generally 500 errors means that they're transient timeouts. Having retries would most likely resolved the issue. That said, let us know if you're still seeing the 500 errors.