Successful organizations always exhibit ambidexterity, balancing exploiting current business demands while exploring new opportunities for future adaptability. The concept of ambidextrous organization originates from giant companies’ innovation practices, little is currently known about how startups pursue ambidexterity. To help startups leverage business opportunities brought by emerging new technologies, particularly telecommunication and artificial intelligence, this study conducts a five-year longitudinal case study of one software-intensive startup evolution towards an ambidextrous organization. Based on primary data and secondary data, including focus group discussions, interviews, and archival materials, we describe two successful innovative attempts of this startup while maintaining its present business. From a leadership-based perspective, we propose a hybrid structure for startup ambidexterity transformation, serving as a middle status between functional designs and ambidextrous structure.