We use Apache Mesos and Apache Aurora to manage the backend jobs that manage the flow of input data to and from the researchers (i.e., downloading them from the researchers systems, preparing them to be sent to volunteers, validating results as they come back from volunteers and packaging sets of result data and sending those sets of data back to the researchers). These two software packages allow us to treat our backend server infrastructure as a single entity--even though it runs across multiple servers--and makes it easier for us to distribute these backend tasks.
We are going to be upgrading this infrastructure over the next 3-4 hours. During this time, we will not be running any of these backend tasks. Volunteers will still be able to get new work and return completed work. However, validation of completed work will be delayed until this upgrade is completed.  I will update you when this work is completed.
Thank you for your patience while we complete this work.
- Jonathan