Where DevOps is a way of working, delivery engineering is a craft. The tools are the same as in any CI/CD effort, but the purpose differs: a DevOps team builds pipelines for its own service, a delivery engineering team builds pipelines as a platform for fifty other teams. The foundations are laid out in Jez Humble and David Farley’s Continuous Delivery.
The need grows with the organisation. With a handful of teams the DevOps mindset is enough; once ten teams solve the same deployment problem in ten different ways, a shared delivery path pays for itself quickly. We have written about where to draw the line in Delivery Engineering vs. DevOps (in Swedish) and about why the same artifact should travel all the way to production in Build once (in Swedish).