This book will explain how to build and deploy enterprise web applications. It will include OSGi, but skip over details that are not really relevant for most use cases. Because there is a clear focus on web applications in the cloud, it will also include architecture, patterns and typical problems in that area, such as tooling and deployment.
Most developers are very much interested in modularity, but it is difficult to get started. Learning resources are still limited, but major improvements in tooling and frameworks in the last year have made it more realistic for developers to jump on this.
