Developing a multi-million LOC highly integrated software product across several locations in numerous time-zones introduces multi-dimensional challenges for the developer operation. Ensuring a frequently available build, configuring and parameterizing tools effectively and efficiently, and guaranteeing that the right content is included for the right release are the top three challenges. Furthermore, to optimize the operation, a reliable and deterministic development environment as well as a lean release coordination structure must be in place. This can be obtained by designing a development operation (DevOps) with a focus on self-service and automation, coupled with tight integration with the developers to continuously optimize the flow of features through the build system to the final artifact delivered to the customer. The Petrel Build Services group is a development operation (DevOps) team offering a range of services for the Petrel E&P software platform. Automated builds, a scalable test and debug environment, tool stack support, code diagnostics, and daily installers are key deliverables. In less than 10 years, the size of the organization being supported by the Build Services group has grown from a team of 10 to hundreds of developers. This has been achieved by maintaining a flat headcount in the group.