Product discovery via ideation and market research

Often, it's easiest to find existing products by coming up with the idea yourself and then checking see if it exists. It's kind of obvious that you should look for products that you need, but what's less obvious is that thinking through how you'd build the product can tell you where to look for it. Frequently, the naïve version of a product idea doesn't exist for a good reason that can be sussed out by an engineer; if you can follow someone else's thought process on how to build it, then you can find their product, as well.