I applied directly to Gitlab via their careers site. The first interview was a screening call with a technical recruiter. This interview lasted for 30 minutes. This part went well for me, I believe, so long as you meet most, if not all, of the job requirements.

The second interview was a technical interview with two senior engineers. It lasted for 90 minutes (with the last 15 minutes at the end reserved for questions and comments). It was a screen sharing/pair programming session with one of the engineers (the other remained silent in the background and audited the call). This session involved reviewing a merge request made to an existing Ruby on Rails codebase. You were given the merge request beforehand to review, run locally, then post any comments.

Though the technical interview went well overall, I later received a regret email stating that Gitlab had chosen to proceed with other candidates whom they felt had greater experience with TDD in Ruby on Rails.

In the screening call, you'll be asked basic questions on your background and experience. So long as you meet most, if not all, of the job requirements, this stage is not a problem.

For the technical interview, you'll be asked to review a merge request with a GitLab engineer. Expect many out-of-the-box questions, especially related to TDD in Rails.