There is no concurrency limit from our side for server customers, you just have to increase the
nomad_clients autoscaling group (AWS) to the desired value and add
parallelism attribute in the config file like below.
version: 2 jobs: test: docker: - image: circleci/<language>:<version TAG> parallelism: 4
More about Parallelism: https://circleci.com/docs/2.0/parallelism-faster-jobs/#specifying-a-jobs-parallelism-level