Research Question and Methodology
The primary research questions addressed are: “What are the key characteristics and goals associated with a virtual monorepo approach?” and “How effectively can a virtual monorepo abstraction layer replicate the developer experience of a unified monorepo workflow while operating on a distributed multi-repository codebase?” These questions are particularly critical given that multi-repository adoption has tripled since 2018, yet organizations struggle with fragmented workflows, high cognitive overhead, and repetitive operational tasks. The study employs a mixed-methods Design Science Research (DSR) approach, combining a multivocal literature review with quantitative performance experiments and qualitative case study observations.
Research Design and Techniques
The study follows a three-phase approach grounded in design science research methodology. First, a comprehensive multivocal literature review synthesized academic and industry sources to establish a conceptual framework defining virtual monorepos through five key characteristics: unified git workflows, enhanced code visibility across repositories, simplified dependency management, coordinated change management, and awareness of multi-repository build and CI/CD pipelines. This framework guided the development of MultiRepoHub, a proof-of-concept browser extension that functions as an abstraction layer over GitLab repositories, enabling virtual workspace creation, unified pull request grouping, and cross-repository dependency analysis. The evaluation employed quantitative experiments measuring cloning time, commit latency, and pull request creation speed, as well as workflow step mapping and a week-long case study with experienced developers at the host organization.
Findings: Efficiency Gains vs. Integration Trade-offs
The results reveal a nuanced picture of virtual monorepo effectiveness. On the performance front, MultiRepoHub demonstrated superior scalability compared to manual multi-repository workflows, with cloning time growing to only 7.694 seconds for 8 projects versus 19.726 seconds for sequential cloning. Commit operations showed even more dramatic improvements, with the tool maintaining stable performance at 0.457 seconds for 8 repositories compared to 1.099 seconds for traditional multi-repo scripts, demonstrating better scalability at scale despite initial overhead. Most significantly, the tool reduced procedural complexity by consolidating fragmented workflows into atomic-like commands, with workflow step counts dropping to near-parity with native monorepos.
However, the qualitative case study revealed critical tensions between workflow simplification and engineering best practices. Developers valued the unified pull request view and automated cross-repository change management, yet encountered challenges with generic commit messages that sacrificed semantic granularity for procedural efficiency. The study found that while the tool successfully reduced cognitive load and improved immediate task efficiency, its benefits were contingent on deep integration with specific development environments and team practices.
Implications and Trade-offs
The research demonstrates that a virtual monorepo is a viable middle-ground strategy for teams seeking monorepo benefits without undertaking costly full-scale migrations. The five-point framework synthesized in this research serves as a diagnostic tool for practitioners to assess existing multi-repository tooling and identify specific friction points. Key findings indicate that practitioners gain the highest return on investment by prioritizing unified code review experiences, as fragmented pull request reviews emerged as the most significant developer pain point. However, the study also revealed a critical abstraction-granularity trade-off: while workflow simplification is desirable, it must preserve semantic integrity and adhere to established engineering practices like meaningful commit conventions. The research concludes that the future of developer tooling lies not in a binary choice between repository architectures but in creating intelligent, context-aware abstraction layers that intelligently balance automation with domain-specific requirements.
