Internationally, challenges were raised towards engineering education concerning the industry's widespread questioning of the lack of practical skills of engineering graduates. Scholars in engineering educational research have tried to better understand professional engineers' practices so as to inform engineering education. Concerning the lack of empirical research in China, particularly from practicing engineers' perspectives, this work explored the perceptions of 22 early and mid-career working engineers from multiple industries in a Chinese context via qualitative interviews on the ways in which the knowledge, skills, and attributes that were essential to their project completion were learnt or developed. Our analyses suggested that such development existed mostly in the process of work completion. In particular, the experiences of participating in multiple projects and reflective thinking and discussions on the projects made the engineer progress fast. Based on the findings, suggestions are proposed for engineering educational practices and future research.