A Technomancer is an engineer that has tapped into the arcane energies, typically through a scientific breakthrough that allowed them to create, sometimes by accident, an artefact to act as a conduit. Using this Arcane Conduit they are able to harness arcane with which they can power their machines, charge weapons, infuse armour and create autonomous machines with arms and legs called Automa. These constructs are semi sentient, given a thought engine by the arcane conduit.
Technomancers don't often leave the workshop, but those that do take their Automa with them, along with arcane infused weapons, with which they have practised martial skills. Their arcane conduit also allow them a degree of spell-like abilities that mimic the arcane powers of a mage, their combined martial and arcane skills make them much sought after by leaders of adventuring parties.