If you really did spend 6 years building this, then it's an excellent example of why you should be vibe coding instead; I don't see anything here that could not be made in 6 minutes instead of 6 years.
Using vibe coding, you will not be able to do such a service in such a short time. In addition to the goal of researching my kanban vision, I also experimented with an architecture that allowed me to achieve the required productivity and ease of development. AI is not that cool yet