The engineer trilogy, book 1 : Devices and desires
K. J. Parker2006

When an engineer is sentenced to death for a petty transgression of guild law, he flees the city, leaving behind his wife and daughter. Forced into exile, he seeks a terrible vengeance - one that will leave a trail of death and destruction in its wake. But he will not be able to achieve this by himself. He must draw up his plans using the blood of others ...In a compelling tale of intrigue and injustice, K. J. Parker's embittered hero takes up arms against his enemies, using the only weapons he has left to him: his ingenuity and his passion - his devices and desires.