From the introduction:
A tinkerer is a master crafter, creator, and manipulator of both the most current developments of engineering and forgotten techniques lost in the fall of ancient civilizations. Many tinkerers explore how magic and engineering mix, developing complex powers of item imbuement and mastering crafting- and mechanicsrelated spells. Others eschew magic as a cheap trick that ignores the brilliance of pure engineering and crafting, or focus on constructs and clockwork or alchemical weaponry, or train to get more out of their tools and magical devices, or kitbash and juryrig what they need when they need it. Of course whatever direction a tinkerer takes when they first start, most branch out into a few different fields of crafting as they grow, learn, and experiment.