As developers, we're biased towards one view of this issue, but it's intellectually lazy of us to just say "Yeah, we deserve it! Because... fairness!" Last December, Joel Spolsky wrote about developer side projects, and honestly, he's right. https://www.joelonsoftware.com/2016/12/09/developers-side-pr... My view: In some companies, depending on their business model, it might be reasonable to ask to own your own work…
You can't prove he wasn't thinking about his next job while he was installing my water heater so I should own that IP.