A recruiter knew that they were looking for a software engineer with a background of working with control systems. They set up a meeting where we met. I was presented with an overall introduction with their problem at hand to which I outlined a principle sketch of how I would decompose the problem into smaller problems and the architecture required to connect those smaller solutions. They liked my suggestion and I was subsequently hired on a contract basis to work for them. Once I started it turned out that they actually wanted me to work on something else.