Case Study: Oscar Health Insurance achieves near-instantaneous CI with HashiCorp Nomad and Docker

Scalable CI at Oscar Health Insurance with Nomad and Docker

Oscar Health Insurance needed a way to run continuous integration at scale across a large monorepo containing multi-gigabyte codebases, thousands of test suites, and sensitive healthcare data. Traditional CI tools and earlier approaches struggled with long startup times, heavy disk I/O, and limited flexibility for their complex build and test workload.

Using HashiCorp Nomad and Docker, Oscar Health Insurance built its own CI engine to schedule and prioritize jobs, isolate tests in containers, and avoid repeated Git checkouts by using cached layered images. The result was near-instantaneous CI job startups and the ability to run about 4,500 nightly build-and-test targets in roughly 45 minutes of wall-clock time instead of about 97 hours of compute time. HashiCorp Nomad also helped Oscar scale reliably with ephemeral EC2 workers and transparent rescheduling when nodes disappeared.

Oscar Health Insurance

Wyatt Anderson

Staff Software Engineer