In this article the authors discuss the process of designing a digital experience to support prospective teachers to learn to enact an equity-based complex practice of mathematics teaching, namely to notice students' mathematical strengths rather than notice gaps and deficits in their thinking. Lesson"Sketch" is a web-based platform purposefully designed to support the work of teacher educators. After theorizing how approximations of practice provide prospective teachers with ways and means for leveraging complex, equity-based pedagogical practices, the authors describe how they used Lesson"Sketch" to design a flexible digital learning experience for prospective teachers in mathematics methods courses. The authors reflect on the design choices they made, the challenges they faced, and the educational potential of their Lesson"Sketch" experience. They conclude by sharing design considerations and challenges that guided their work together and that could guide other mathematics teacher educators to support prospective teachers' learning of complex pedagogical practices.