Okay, after some long investigations; we've found some temporary fixes to help with some of the scale problems we're dealing with. We'll continue to improve on this with a more thoughtful long-term solution -- but in the meantime we'll be monitoring our service closely. Thank you all for your patience!

We’re investigating an issue with our sessions API that is impacting some users due to a larger number of requests than usual. We’re working to fix the problem as quickly as we can. We’ll share another update shortly.