Well, to be fair, the live start was only possible because we had the data service contract to get live updates for perfect team
The biggest flaws was that it was the first year, so sometimes we literally didn't know what to expect. Thankfully the data provider didn't do something like change up the formats on us, but literally there were many times where we just had to wait and see what the data looked like before we could do anything. So, for example, draft picks, I had no idea if the players would show signed on the teams, be missed entirely, show up separately in the system, have proper IDs associated with them, etc... We just had to wait and see, and then react to what we got. Even stuff like how they handled (or failed to handle) minor league transactions obviously was not good for our use case, but we tried to figure out a way to work with what we got.
But yeah, it was definitely a learning experience. We at least have a year under our belts with it now, so hopefully we can improve further on it going forward.