This praxis-oriented article reports on the design, implementation, and evaluation of an upper-level online German course aimed at advancing the second language (L2) proficiency of US university students. Drawing on the noticing hypothesis and empirical L2 acquisition research, the study underscores the necessity of combining attention to linguistic form and meaning to optimize learning. The course design leveraged the multiliteracies approach and a multimodal guided reading framework to address the challenge of integrating multiple linguistic levels and literacy dimensions, prioritizing reading and development of the vocabulary knowledge and utilizing technology to present materials in various formats conducive to multimedia learning. The study presents both an affordance-based and evidence-based evaluation of the course. Findings indicate significant improvements in vocabulary size, high engagement levels, and positive learner perceptions toward the course materials and assignments. These outcomes suggest that the complex interplay of the focus on meaning and form within a multimodal online learning environment can effectively enhance L2 proficiency. The article concludes with recommendations for educators looking to implement similar courses, offering a model that can be adapted to various upper-level university contexts.