I would work, not for my current employer (or any employer) but for myself. I would setup a one-man LLC or similar and build products I'm proud of. If some of them work out and bring money, good! If not, also good.

Also, I wouldn't work 40h/week on it. More like ~10h/week. I would take it very slow, focusing on the parts that I enjoy the most (like deciding the font of the website for my product, or deciding the dir. structure of my backend, or thinking about that algorithm for days or weeks until I got it right).

I don't like tech companies. I work for one because they pay good. I love my career nevertheless and I become better at it in my free time (that's another reason tech companies pay me good money, because I'm good at it... but I couldn't care less about their products; I pass their interviews with a fake facade)