The integration of digital technology in language education requires pre-service teachers not only to master technology but also to connect it with instructional content through Technological Content Knowledge (TCK). Project-Based Learning (PjBL) provides an authentic context for applying technology, but project complexity can place demands on learners’ technological readiness. Microlearning, meanwhile, supports focused learning of technological knowledge and procedures, yet its functional relationship with PjBL remains unclear. This study aims to synthesize the literature on PjBL and Microlearning and examine their potential complementary relationship in supporting TCK development among pre-service language teachers. A narrative literature review with thematic synthesis was conducted on 35 Scopus-indexed articles published between 2021 and 2026, comprising 18 Microlearning studies and 17 PjBL studies, including 10 studies focusing on pre-service language teachers. The synthesis indicates that PjBL facilitates skill development through project activities but can present challenges related to technological readiness; Microlearning supports focused learning of technology and procedures; and a functional gap exists between the two approaches. Drawing on TPACK/TCK, scaffolding, and Cognitive Load Theory, Microlearning is conceptually positioned as a prerequisite cognitive scaffold before relevant PjBL activities. This proposition reframes Microlearning as preparatory technological support that may facilitate technology–content integration and TCK development, while its effectiveness remains to be empirically examined.