tldr: I sent a different ticket to a different user due to race condition Problem We had a consumer which would listen to transaction events and based on that would issue tickets to the corresponding user. Since that was something that could be done concurrently I designed a flow to set up a threadpool and assign the tasks. Problem was that ‘data’ was part of the object’s state and not a parameter so multiple task could see and modify the ‘data’ resulting in inconsistent behavior.