What are things you'd recommend doing to develop skills to be a good cofounder? How would you go about finding opportunities?
However, if you are hell-bent on becoming a technical co-founder, make sure that you bring some other skills to the table. You will need to make sure that you have the resources to pay your AWS bills, be able to hire people and then fire them when necessary. Furthermore, you will need some measure of product skills (because at this stage, you will need to determine the featureset of the products).
So this is why you should go for a PE role, and then if you find the right idea, go for a co-founder role.