Have you heard of the SOLID principles? You have? Can you explain them all? And make your colleague understand them, and why they are useful? Ok, in that case you should stay away from this session. If not, you should definitely go to this session, as it goes through each one of the principles, explaining what it means and why it is useful. You will also be shown C# code examples explaining how they help you, and what problems you solve by adhering to them.