Development team workflow (Kanban)
I'm trying to apply Jira's Kanban to our development team to make our work more manageable and predictable. The development team consists of three backend Java developers and one tester. The developers implent new features, write unit tests, fix bugs. A tester performs manual testing and new writes tests. We came up with the following workflow: READY_FOR_DEVELOPMENT, DEVELOPMENT, CODE_REVIEW, TESTING, DONE.
But it never happens that we have a large amount (or zero) of tasks in one column. I don't feel like this board is helping us in any way.
Maybe the steps we have chosen for our wolrkflow are too trivial? What Kanban workflow have you used in development teams (consisting of developers and testers)? How did it help your team?
There's more to Kanban than just using a board to visualize the work. It seems like you may be missing two key aspects - a pull system and work-in-progress limits.
The workflow that you describe seems mostly correct. I would add one additional state between CODE_REVIEW and TESTING - READY_FOR_TESTING. This would help implementing a pull system, where the tester can clearly see what work has completed code review and choose which work item(s) from those to begin testing.
In the definition of the board, you didn't mention work-in-progress (WIP) limits. Most of the columns should have WIP limits. Once you establish these limits, work should not enter a column unless it has room under its WIP limit. This is a signal to the team to start moving work to the DONE state before starting new work and moving it to the workflow.
I believe that making a pull system more explicit and defining WIP limits will reveal bottlenecks in your process, which can then be addressed by the team.