At Taxfix, we specialise in providing consumer-facing tax services at scale, for the German market. Achieving this requires close collaboration between tax advisors and service designers. Tax advisors are traditionally trained to be precise, avoid mistakes and vigilantly guard against errors. This contrasts sharply with service designers, who are inclined to take risks, embrace uncertainty, and value creative experimentation. In this article, we share insights on our recipe for how to find a productive mode of collaboration between two disiplines which on the face of it seem to be worlds apart.