Regular Circle CI. I do not have access to the v2 beta. For comparison here is the same Dockerfile built with Circle CI, it took 3m30s: https://cl.ly/0U1c2Q1n2S20/Image%202017-03-06%20at%209.50.31... and Google Cloud Container Builder: https://cl.ly/3E1c3l1L2Q3o/Image%202017-03-06%20at%209.52.01... although Cloud Container Builder does not list how long each step it takes, it totals 1m10s.