We have two developers working on the same project. One is doing the front end and the other doing the back end.
Everything is working well, however we have come across the developer doing the back end stuff and getting though it faster than what the front end developer is working on. Therefore the back end dev skips ahead to other stories that he needs to work on.
I'm guessing this is fine but I'm not sure what happens when the front end developer goes in and ends up not being able to get though all of the stories, and we have to stop because time has been spent ahead by the back end developer doing his tasks out of the priority order.
Should the back end developer wait until the front end developer to catch up or should he keep going?
If he keeps going, what do you do about the budget and not completing the sprint?