The topic of SQL Server concurrency is one that many people want to understand really well, but at the same time is one that doesn't get the needed attention for some reason. In addition, isolation levels can play a huge role in both the performance and the scalability of every application and so the proper choice of isolation level is crucial. In this session we are going to go deep into the world of SQL Server isolation levels and see what is the behaviour of each one of them. We will discuss how we should approach the final decision on which level we should go with and how we can actually effectively troubleshoot concurrency issues. Last, but not at least, we will take a look at what is going on behind the scenes when our applications work and what differentiates one isolation level from the other. The session is suitable for both application developers and DBAs who want to advance their knowledge in the unending world of SQL Server concurrency.