Sorry, I have never dealt with Dev Ops. I am working mostly alone in my current team at work, too. But from what I learned about Dev Ops, it is not something you would implement for small teams (1-2 devs). In that kind of situation I would rather (and this is purely my personal opinion with not much knowlegde about your situation) use an agile Kanban task board with an extended backlog in order to assign tasks to other people which they might work on out-of-order. In addition, using sprints with defined milestones to sync with the other developers will help you tremendously. You might want to take a look at "zero bug development" to order you milestone items. Use the skateboard principle (MVP) to build your application and get feedback.

So you might set up a git repository, make a master branch and a stable branch. You make one new personal branch per feature and, when you are done with your feature, merge it into master. At the end of the sprint, you make sure whatever you got in master works as planned and you do not have any more bugs on your list. Move master into stable and then give it to your client for feedback while you work your next milestone.

As for the extended backlog, that's the place where you assign tests and collaborate, when you find out you have topics you need to work on with someone else (the other dev).