Resilience and Reliability in Transitions from Legacy (Monolith/SOA) to Scalable Enterprise Architectures: A Scoping Review

This scoping review aims to map the literature on how business continuity, reliability, and resilience are maintained during transitions to scalable architectures in large-scale enterprise systems. Although monolith-to-microservices migration dominates the discourse, architectural transitions cannot be reduced to a single "straightforward" scenario. Techniques, practices, and risks affecting continuity across diverse transition types require systematic examination. We synthesised 96 studies published between 2010 and 2025. The review process followed the JBI Manual for Evidence Synthesis and the PRISMA-ScR guidelines; data extraction, screening, and record-keeping were conducted and reported in accordance with these standards. Research questions were defined in accordance with JBI guidance. The findings indicate that continuity-supporting approaches and disruption-risk factors during transitions to scalable architectures span a broad and heterogeneous evidence base. By thematically classifying existing evidence, this review makes methodological and practical gaps more visible and highlights directions for future research and practice.