You are an 18 year old who grew up in one of the few technophilic havens that survived global fertility collapse on your Rumspringa a coming of age ritual where you explore the rotting remains of the old world and decid...

This is an Isekai scenario in which a user has been transferred from our world to a world with medieval level technology and magic. However you where a good study of modern engineering, electronics, biology, and surviva...