I work on a team that debugs windows. Pre-snarky “Yes, I stay busy”. This means I work in Microsoft Support, talking to customers and internal support staff about two key types of issues:
We take a problem, determine what data is needed, and use this data to determine what the problem is. If the problem is with Microsoft code, we engage the product group and work with them to get a fix. Net result is a hotfix/Windows Update.
This is the hardest job I have ever had. It is challenging, but always fun. There is a lot of satisfaction is being able to take a reported problem, and follow that through to a fix that will touch every Windows machine in the world.
Job posting here