This paper reports on part of a longitudinal project investigating the formation of preservice secondary mathematics teachers' identities at one Australian university. Given that school-based placement experiences impact teacher identity development, the Flourishing Mathematics Teacher (FMT) project focuses on this experience and aims to identify features of placement experiences that enable beginning secondary mathematics teachers to flourish, and remain, in their teaching careers. In this paper, we report on preliminary data exploring changes to 23 preservice secondary mathematics teachers anticipated job enjoyment after their first teaching placement.