All services have been restored with logins and signups working as they should. The incident was caused by an expired SSL certificate failing to update due to an integration issue with our security supplier. To note, although login and signup services were interrupted during the incident, submissions were functioning throughout and no data was lost.
We sincerely apologize for this outage and any inconvenience we may have caused. Our engineering teams will review the details and ensure we put measures in place to prevent this from happening again.