GitLab is a single application for the entire DevOps lifecycle. Sourcegraph and GitLab integrate well together (and offer largely complementary, not overlapping, features).
- GitLab integration with Sourcegraph (Sourcegraph documentation)
- Upcoming native integration: GitLab blog post and Sourcegraph blog post
GitLab offers code search, which is acceptable for smaller teams using GitLab with simple/infrequent code search needs. The main pain points we hear are lack of support for literal/regexp queries and filters, and that the UI is not optimized for searching across multiple repositories. For medium and large organizations, Sourcegraph is a better alternative to GitLab's built-in code search.