Software developers use software products to design and develop new software products for others to use. Research has introduced a concept of developer experience inspired by the concept of user experience but appreciating also the special characteristics of software development context. It is unclear what the experiential components of developer experience are and how it can be measured. In this paper we address developer experience of Vaadin Designer, a graphical user interface designer tool in terms of user experience, intrinsic motivation, and flow state experience. We surveyed 18 developers using AttrakDiff, flow state scale, intrinsic motivation inventory and our own DEXI scale and compare those responses to developers’ overall user experience assessment using Mann-Whitney U test. We found significant differences in motivational and flow state factors between groups who assessed the overall user experience either bad or good. Based on our results we discuss the factors that construe developer experience.