Software development is constantly evolving, adapting to emerging technologies and development paradigms while leveraging advancements in communication technologies and work modes. We conduct an exploratory case study in a large software organization to investigate how the development paradigm and the formality of communication channels affect written communication within hybrid teams. We perform statistical and content analysis of written conversations from 20 projects involving two software products that use industry adaptations of the Waterfall model and of Scrum, respectively. We found that in agile-developed projects, communication related to the execution-monitoring-control phase of the Project Management Life Cycle is more prevalent, and communication related to the initiation phase occurs more frequently in informal channels. For both project types, communication primarily pertains to the software construction phase of the Software Development Life Cycle. After annotating communication contents using speech acts, representatives are found to be prevalent in informal channels for agile-developed projects, directives are more prevalent in informal channels for waterfall-developed projects, and expressives are more frequent in informal channels for both project types. We provide empirical evidence that development paradigms and communication channel formality impact written communication, with agile-developed projects showing more collaborative interactions in informal channels compared to waterfall-developed projects. Editor’s note: Open Science material was validated by the Journal of Systems and Software Open Science Board . • We analyze the written communication of 20 projects in the software industry. • We compare the projects in terms of development paradigm and channel formality. • We applied statistical and content analyses to the communication contents. • We find that development paradigm and channel formality impact written communication.

Context: Organizations are increasingly connecting software applications using Application Programming Interfaces (APIs) to share data, services, functionality, and even complete business processes. However, the creation and management of APIs is non-trivial. Aspects such as traffic management, community engagement, documentation, and version management are often rushed afterthoughts. Objective: In this research, we present and evaluate a focus area maturity model for API Management (API-m-FAMM). A focus area maturity model can be used to establish the maturity level of an organization in a specific functional domain described through a number of areas. The API-m-FAMM addresses the areas Lifecycle Management, Security, Performance, Observability, Community, and Commercial. Method: The model is constructed using established methods for the design of a focus area maturity model. It is grounded in literature and practice, and was developed and evaluated through a systematic literature Review, eleven expert interviews, and five case studies at software producing organizations. Result: The model is described in detail, and its application is illustrated by six case studies. Conclusions: The evaluations are reported on, and show that the API-m-FAMM is an efficient tool for aiding organizations in gaining a better understanding of their current implementation of API management practices, and provides them with guidance towards higher levels of maturity. The detailed description of the construction of the API-m-FAMM gives researchers an example to further support the available methodologies, specifically how to combine design science research with these methodologies. Additionally, this study’s unique case study design shows that maturity models can be successfully deployed in practice with minimal involvement of researchers. The focus area maturity model for API Management is maintained on www.maturitymodels.org , allowing practitioners to benefit from its useful insights.

Event sourced systems are increasing in popularity because they are reliable, flexible, and scalable. In this article, we point a microscope at a software architecture pattern that is rapidly gaining popularity in industry, but has not received as much attention from the scientific community. We do so through constructivist grounded theory, which proves a suitable qualitative method for extracting architectural knowledge from practitioners. Based on the discussion of 19 event sourced systems we explore the rationale for and the context of the event sourcing pattern. A description of the pattern itself and its relation to other patterns as discussed with practitioners is given. The description itself is grounded in the experience of 25 engineers, making it a reliable source for both new practitioners and scientists. We identify five challenges that practitioners experience: event system evolution, the steep learning curve, lack of available technology, rebuilding projections, and data privacy. For the first challenge of event system evolution, we uncover five tactics and solutions that support practitioners in their design choices when developing evolving event sourced systems: versioned events, weak schema, upcasting, in-place transformation, and copy-and-transform.

Workload intensity in terms of arrival rate and think-time can be used accurately simulate system performance in traditional systems. Most systems treat individual requests on a standalone basis and resource demands typically do not vary too significantly, which in most cases can be addressed as a parametric dependency. New frameworks such as Command Query Responsibility Segregation and Event Sourcing change the paradigm, where request processing is both parametric dependent and dynamic, as the history of changes that have occurred are replayed to construct the current state of the system. This makes every request unique and difficult to simulate. While traditional systems are studied extensively in the scientific community, the latter is still new and mainly used by practitioners. In this work, we study one such industrial application using Command Query Responsibility Segregation and Event Sourcing frameworks. We propose new workload patterns suited to define the dynamic behavior of these systems, define various architectural patterns possible in such systems based on domain-driven design principles, and create analytical performance models to make predictions. We verify the models by making measurements on an actual application running similar workloads and compare the predictions. Furthermore, we discuss the suitability of the architectural patterns to different usage scenarios and propose changes to architecture in each case to improve performance.

Evolving software systems includes data schema changes, and because of those schema changes data has to be converted. Converting data between two different schemas while continuing the operation of the system is a challenge when that system is expected to be available always. Data conversion in event sourced systems introduces new challenges, because of the relative novelty of the event sourcing architectural pattern, because of the lack of standardized tools for data conversion, and because of the large amount of data that is stored in typical event stores. This paper addresses the challenge of schema evolution and the resulting data conversion for event sourced systems. First of all a set of event store upgrade operations is proposed that can be used to convert data between two versions of a data schema. Second, a set of techniques and strategies that execute the data conversion while continuing the operation of the system is discussed. The final contribution is an event store upgrade framework that identifies which techniques and strategies can be combined to execute the event store upgrade operations while continuing operation of the system. Two utilizations of the framework are given, the first being as decision support in upfront design of an upgrade system for event sourced systems. The framework can also be utilized as the description of an automated upgrade system that can be used for continuous deployment. The event store upgrade framework is evaluated in interviews with three renowned experts in the domain and has been found to be a comprehensive overview that can be utilized in the design and implementation of an upgrade system. The automated upgrade system has been implemented partially and applied in experiments.