Architecting for Scale, 2nd Edition

Part II. Tenet 2. Modern Application Architecture: Using Services

Modern software requires the use of modern application architectures. Modern application architectures require moving away from monolithic applications and embracing service-based architectures.

Monolith applications are extremely hard to scale, both from a traffic scaling standpoint and from the standpoint of your ability to scale the size of your organization to work on the application. The larger the monolith, the slower it is to make changes to the application, the fewer the people who can work on it and manage it effectively, and the greater the likelihood that traffic variations and growth will negatively impact availability.

Service-oriented architectures solve these problems by providing greater flexibility in scaling based on traffic needs, as well as providing a scalable framework to allow larger development organizations to work on the application, thus allowing the applications themselves to get larger and more complex.