Monolithic-to-Microservices Migration Processes : An Interview Study of Migration Processes According to Practical Experience

Background. Software evolution of enterprise systems is a critical aspect of modern software engineering. Most of the costs in software lifecome from evolution and maintenance, scalability and maintainabilityemerge as critical quality attributes. Many enterprise applications areoften built on technology stacks that have reached the end of their lifecycles or with architectural shortcomings that hinder flexibility andgrowth. Microservices architecture arose to address these issues. Objectives. The aim of this thesis is to obtain detailed and qualitative data with the practitioners’ narratives based on their experiencewith migration processes from MA to MSA and to compare the datagathered with migration processes that are proposed in the literature. Methods. The research was divided into 3 parts. A literature reviewto search for publications that propose processes for migrating frommonolithic architectures to microservice architectures, so that we canstudy those processes. Followed by a qualitative interview to get thepractitioners narrative on the proposed steps for a migration foundin the literature review. And a thematic analysis to process the datacollected from the interviews to then compare it with the steps foundin the literature review. Results. The literature review produced 6 migration processes thatmet our requirements. This factorization of the processes into constituent steps informed the design of the interview. The thematicanalysis done on the resulting dataset generated 14 major themes and41 sub-themes on the subject of MA-to-MSA migrations. The datasetincluded validation ratings for each migration step, as well as scoresfor the practitioners’ migration process in regard of achieved maintainability, scalability, and overall effectiveness of the migration. Conclusions. This study contributes to evaluate migration processesfound in the literature that migrates from monolithic architecture tomicroservices architecture based on the practitioners narrative. It results into a validation of every migration step found ending into anon-crucial, nice to have or must-have grading. That grading and thethematic analysis will be the justification and answer to our researchobjectives. The thesis will also propose some future work that can bebased on the findings of this study