Drupal consulting since 2007 has been in stabilizing and automating existing Commercial Drupal installations:
1. Stabilize environment: Tuning LAMP and Drupal.
2. Stabilize deployment, usually involving the cron instance.
3. Audit QA methods and advise best practices accordingly.
4. Tune Agile methods to include a DevOps workflow.
5. Modify and tune Architecture to allow Horizontal WebHead Scaling.
6. Scour a lot of logs and queries.
Once these goals are accomplished a Drupal based start-up can compete with the best on-line companies in their market space, by realizing Continuous Delivery.