A practice-based engineering degree, in which students worked on real-world, team-based projects from day one and throughout their course, was designed to address the need for employability skills in a rapidly changing world. Teaching mathematics in this way required a very different approach to the lecture-exam based model prevalent in most engineering degrees. In order to ensure all students developed the fundamental skills and knowledge required of engineers, a micro-credential based curriculum was developed where micro-credentials were mapped to projects and delivered "just-in-time". The curriculum contained forty-eight explicit mathematical micro-credentials in the areas of measurement and geometry, algebra, calculus, and statistics and probability as well as many more micro-credentials in other areas of curriculum that contain mathematical skills, from physics to project budgeting. Mathematical competencies were used as a framework in the design and analysis of the micro-credentials. This paper presents a description of, and reflection on the successes and challenges in implementing this model of teaching mathematics in engineering.