Hello,
Olivier here (CEO Tomorrow)
Indeed we're running on GCP, using a mixture of Python and Node. In terms of the approach, I suggest checking out our blog (https://www.tmrow.com/blog) and this talk (https://www.youtube.com/watch?v=PAelZb2ZYwI) which might provide a bit of clarity.
Also, feel free to join our Slack at https://slack.tmrow.com to ask your questions!